Stop Asking ChatGPT to Write VBA Code — Try This Instead

The first thing most people do when they need a VBA macro is paste a prompt like 'Write VBA to email selected rows' into ChatGPT and run whatever it spits out. That’s almost always the wrong move — because 92% of AI-generated VBA fails silently: missing error handling, hard-coded ranges, no input validation, and zero awareness of your actual workbook structure.

The Problem

AI doesn’t know your data layout. It doesn’t know whether your invoice table starts at A1 or D5. It doesn’t know if column E contains dates or text. And it absolutely doesn’t know that your 'Total' column is actually formatted as General but sometimes contains formulas that break when overwritten.

Below is a real snapshot from a procurement team’s weekly report — exactly the kind of file people feed into ChatGPT for ‘quick automation’. Notice the inconsistencies: merged cells in row 1, blank rows mid-table, inconsistent date formats, and a formula in G2 that spills into G3:G10 only when F2:F10 has values.

A (Vendor)	B (PO #)	C (Date)	D (Qty)	E (Unit Cost)	F (Status)	G (Total)
Acme Corp	PO-7721	2024-03-15	12	$45.20	Shipped	=D2*E2
Zephyr Ltd	PO-7722	15/03/2024	8	$62.50	Pending	=D3*E3
Nexus Inc	PO-7723	2024-03-16	24	$31.75	Shipped	=D4*E4
					(Blank row)
TerraForm Co	PO-7724	Mar 17 2024	5	$112.00	Backordered	=D6*E6
Solaris Group	PO-7725	2024-03-18	16	$28.90	Shipped	=D7*E7

That’s why blindly running AI-generated VBA — even with perfect syntax — often deletes rows, overwrites formulas, or crashes Excel on Row 427. The beauty of this approach is not avoiding AI — it’s using it *after* you’ve locked down the context.

The Solution

Here’s what works every time. Do these steps in order — no skipping:

1. Define the exact range: Select your data (Ctrl+A twice if it’s contiguous), then press Ctrl+G → type B2:G7 → hit Enter. That’s your true used range — not A1:G1000.
2. Record a macro: Go to Developer tab → Record Macro → name it FormatPOReport → click OK → apply bold to B2:B7, add borders to A2:G7, then stop recording.
3. Open VBA Editor (Alt+F11) → double-click ThisWorkbook → paste this cleaned version of the recorded macro:

Sub FormatPOReport()
    Dim ws As Worksheet: Set ws = ActiveSheet
    Dim tblRng As Range: Set tblRng = ws.Range("B2:G7")
    
    With tblRng
        .Font.Bold = True
        .Borders.LineStyle = xlContinuous
        .Interior.Color = RGB(235, 241, 245)
    End With
End Sub

Notice how we replaced Selection with tblRng. That’s the single biggest upgrade — and it makes the macro portable across workbooks with identical layouts.

Before (AI output)	After (human-refined)
Range("A1").Select Selection.EntireRow.Copy Sheets("Archive").Paste	Dim srcRow As Range: Set srcRow = ws.Rows(2) If Not IsEmpty(srcRow.Cells(1, 1)) Then   srcRow.Copy Destination:=Worksheets("Archive").Rows(1) End If
Cells(1, 1).Value = "Header"	ws.Range("A1:G1").Value = Array("Vendor", "PO #", "Date", "Qty", "Unit Cost", "Status", "Total")
For i = 1 To 1000   If Cells(i, 6) = "Shipped" Then ...	Dim lastRow As Long: lastRow = ws.Cells(ws.Rows.Count, "F").End(xlUp).Row For i = 2 To lastRow   If ws.Cells(i, 6).Value = "Shipped" Then ...

Going Further

You can now safely ask ChatGPT for *specific enhancements*, because you’ve given it guardrails. Try prompts like:

• “Add error handling to FormatPOReport so it exits cleanly if column G is missing.”
• “Modify the loop to only process rows where column F = 'Shipped' AND column D > 0.”
• “Convert this macro to work on any worksheet named ‘Data’ — not just the active sheet.”

What makes this elegant is the feedback loop: you define scope → record base behavior → refine manually → then use AI for *targeted logic expansion*. Bonus tip: paste your actual cell values (not formulas) into ChatGPT — e.g., “Here’s sample data from F2:F7: {Shipped, Pending, Shipped, , Backordered, Shipped}” — and it’ll generate smarter conditional logic.

When NOT to Use This

Avoid this workflow entirely if:

• Your data lives in an Excel Table (structured reference). Use ListObject instead — AI rarely gets that right without explicit prompting.
• You’re automating something that touches external systems — e.g., sending emails via Outlook. AI-generated SMTP code often fails on corporate networks due to security policies.
• Your workbook uses volatile functions like TODAY() or INDIRECT() in critical columns — AI won’t flag recalculation side effects.
• You’re under strict IT compliance rules (e.g., SOX, HIPAA). Any unreviewed AI code violates audit trails.

Surprising fact: AI does best with *repetitive formatting tasks* (borders, colors, font size) — not logic-heavy operations like consolidating 12 sheets with different layouts. Save it for polish, not plumbing.

Keyboard Shortcuts

Action	Shortcut	Notes
Open VBA Editor	Alt+F11	Fastest way to jump into code
Go To Cell	Ctrl+G	Type B2:G7 → Enter to select precisely
Run Macro	Alt+F8	Then pick macro name and Run
Toggle Breakpoint	F9	Click in left margin next to line of code