Excel VBA Modifier Skill

Safe VBA code modification with xlwings

Overview

Automates VBA code modifications while ensuring safety:

• Verify Trust Center allows programmatic VBA access

• Read VBA module code from .xlsm files

• Write/modify VBA module code safely

• Run test macros to validate changes

• Automatic backup before modifications

When to Use

• Modifying VBA code: Safe xlwings-based editing

• Testing macro changes: Run macros to validate

• Debugging VBA: Read module code without manual editing

• Batch updates: Apply changes to multiple macros

• Following safety rules: Automatic backup and validation

Usage

Check Trust Center permissions

conda run -n excel python script/modify_vba.py check-trust perturb_inform.xlsm

Read a VBA module

conda run -n excel python script/modify_vba.py read perturb_inform.xlsm Module2

Write/modify a VBA module (from file)

conda run -n excel python script/modify_vba.py write perturb_inform.xlsm Module2 new_code.vba

Run a macro to test

conda run -n excel python script/modify_vba.py run perturb_inform.xlsm BuildMetaSummary

Features

Trust Center Checking

conda run -n excel python script/modify_vba.py check-trust file.xlsm

Output:

✓ Trust Center check passed ✓ VBA project access allowed

Reading VBA Code

conda run -n excel python script/modify_vba.py read file.xlsm Module2

Outputs module code to console (can redirect to file).

Writing VBA Code

Write from file

conda run -n excel python script/modify_vba.py write file.xlsm Module2 new_code.vba

Automatically creates backup first

Then replaces module with new code

Running Macros

Test macro after modification

conda run -n excel python script/modify_vba.py run file.xlsm BuildMetaSummary

With arguments (if applicable)

conda run -n excel python script/modify_vba.py run file.xlsm Sub1 arg1 arg2

Safety Features

✓ Automatic backup before modifications ✓ Trust Center validation ✓ Test macro execution ✓ Error handling and rollback ✓ Windows only (COM access)

Integration with Other Skills

• excel-backup-manager: Auto-backup before writes

• excel-inspector: Understand VBA structure

• excel-na-utils: Helper functions for VBA code

Requirements

• OS: Windows only (xlwings COM access)

• Package: xlwings

• Trust Center: Must allow programmatic VBA access

• Excel: Installed and configured

Error Handling

Error Solution

Trust Center blocked Enable in Excel: File > Options > Trust Center

Module not found Use excel-inspector to list modules

Write failed Check file isn't open in Excel

Macro failed Check syntax in new VBA code

Workflow

User request ↓ Check Trust Center ↓ Create backup (via excel-backup-manager) ↓ Read current module ↓ Write new module ↓ Run test macro ↓ Report success/failure

Files

• vba_modifier.py : Core VBA modification logic

• trust_center_checker.py : Trust Center validation

• CLI: script/modify_vba.py