Claude Cowork does exactly this (accessing the internet is inherent, it can install and then use Stable Diffusion and other open source LLMs).
Yesterday I used Claude Code to incorporate changes to a working document (Word/DOCX) based on a meeting transcript. It added new sections and reorganized the DOCX document, creating a new copy, retaining formatting.
Claude Cowork has direct integrations into PowerPoint and Excel (specific installers), but it doesn't have such for Word documents.
So instead, it uses tools. I just asked it to make the changes, which it did (4 times perfectly, I recorded it for internal purposes and messed up the recording a few times).
Here are the tools it used along with the explanations:
Here's what I used to complete the work:
Document manipulation followed the DOCX skill's unpack/edit/repack workflow. I unpacked the .docx file (which is really a ZIP archive) into its raw XML components, directly edited the word/document.xml file, then repacked everything back into a valid .docx. This preserves all original formatting â" styles, fonts, table layouts, numbering, bookmarks â" because you're working with the same XML the document was built from.
Key tools and techniques:
The Read tool let me examine the source files (transcript, XXXX, process use cases) and read the DOCX skill instructions. Since document.xml was too large to read in one pass, I used offset/limit parameters to read it in sections.
Pandoc converted the .docx to markdown so I could get a readable overview of the full document structure without wrestling with raw XML. I used this both before editing (to understand the layout) and after (to verify the result).
Grep helped me find specific line numbers in the XML â" locating exact insertion points for each edit by searching for heading text, table boundaries, and style markers.
The Edit tool made targeted changes to the XML, inserting new paragraphs, table rows, and sections while matching the surrounding style patterns (w:pStyle, w:rPr, w:numPr, w:cnfStyle attributes) copied from adjacent elements.
Bash handled the unpack/repack scripts (Python-based, provided by the DOCX skill), directory navigation, and the pandoc conversions.
The repack script ran its own validation â" checking paragraph counts and XML well-formedness â" which confirmed everything passed before producing the final .docx.