Extracting the criticmarkup to docx functionality

[ttxtea]

I think the conversion of criticmarkup to docx comments is of general interest. The criticmarkup.lua filter nicely capsulates the back-conversion of docx comments to criticmarkup, but I am wondering as a naive user, where in the code conversion of criticmarkup to docx is to be found. Could it easily be written as a lua filter for general useage in pandoc, as well?