com-excel-editor

Full-fidelity Excel workbook editing through Windows COM automation -- formulas, formatting, notes, threaded comments, charts, and SharePoint integration.

Why COM instead of openpyxl?

Capability	COM (this skill)	openpyxl
Preserve formulas on save	Yes	Partial (loses volatile formulas)
Preserve macros / VBA	Yes	No (.xlsx only)
Open SharePoint / Teams files	Yes (by URL)	No
Notes-to-Comments conversion	Yes	No
Conditional formatting fidelity	Full	Partial
Charts and pivot tables	Full	Limited
Platform	Windows only	Cross-platform

Installation

As a Claude Code skill

Place the com-excel-editor/ folder under ~/.claude/skills/. Claude Code will automatically discover it via the SKILL.md frontmatter.

As a standalone module

pip install pywin32
# Copy scripts/com_excel_editor.py into your project

Requires Windows with Microsoft Excel installed.

Quick Start

Local file

from com_excel_editor import ExcelWorkbook

with ExcelWorkbook() as wb:
    wb.open("report.xlsx")
    sheet = wb.get_sheet("Summary")
    sheet.write_cell(2, 3, "Updated")

SharePoint / Teams URL

from com_excel_editor import ExcelWorkbook

url = "https://tenant.sharepoint.com/:x:/r/teams/Team/Shared%20Documents/General/report.xlsx?d=xxx&csf=1&web=1&e=xxx"

with ExcelWorkbook() as wb:
    wb.open(url)
    sheet = wb.get_sheet("Data")
    value = sheet.read_cell(1, 1)

Features

Workbook lifecycle: open, save, save_as, export_pdf, close

Sheet operations: get_sheet, add_sheet, delete_sheet, sheet_names

Cell operations: read_cell, write_cell, read_range, write_range

Find & Replace: find_replace with case sensitivity options

Notes (legacy): get_note, add_note, delete_note, get_all_notes

Threaded Comments (modern): add_comment, get_comment, reply_to_comment

Notes-to-Comments conversion: convert_note_to_comment, convert_all_notes_to_comments

Formatting: format_cell, autofit, set_column_width

Workbook info: get_property, set_property

Raw COM access: wb.app (Application), wb.doc (Workbook) for direct COM calls

Notes-to-Comments Conversion

The key unique feature of this skill. Modern Excel has two annotation types:

• Notes -- legacy yellow sticky-notes (pre-Office 365 "Comments")
• Comments -- modern threaded discussions with replies and @mentions

This skill converts Notes to Comments in bulk, which is not possible through the Excel UI or openpyxl.

with ExcelWorkbook() as wb:
    wb.open("legacy_workbook.xlsx")

    # Convert a single cell
    sheet = wb.get_sheet("Sheet1")
    sheet.convert_note_to_comment(2, 3)

    # Convert an entire sheet
    sheet.convert_all_notes_to_comments()

    # Convert the entire workbook
    total = wb.convert_all_notes_to_comments()
    print(f"Converted {total} notes across all sheets")

Key Design Decisions

1. Performance optimization -- The context manager disables ScreenUpdating and sets Calculation to manual mode on entry. This prevents Excel from repainting and recalculating after every cell write, turning bulk operations from minutes to seconds.

2. BGR color order -- Excel COM uses BGR byte order internally. The format_cell method accepts standard (R, G, B) tuples and converts to BGR automatically, so you never have to think about it.

3. 1-based indexing -- All row and column parameters are 1-based to match Excel's native COM convention. read_cell(1, 1) reads cell A1.

4. No tracked changes -- Unlike Word, Excel has no built-in tracked changes API. This is a platform limitation, not a missing feature. If you need an audit trail, log changes to a separate sheet.

License

MIT