I also have a ModernCV based CV, and to the few recruiters who ask for a word based CV I just use latex2rtf, a tool available in most distributions and through homebrew as well.
While .rtf is not .doc, it is a format that can be opened by all major word processors, and can be easily edited and converted to .doc as well. While it doesn't keep all of the subtle niceties of ModernCV, it does a fairly good job in keeping the generic structure of the document, which is what recruiters need anyway. Yes, it will look like a website without CSS applied, but it will retain the main structure (job title headers, bullet points, additional details provided, etc.), which most CVs need anyway. If the recruiter wants to edit it then can add their own design to this easily.
Note although some recruiters accept PDFs, they will try to import it to word and edit it, which sometimes result in horrendous results. I once saw the CV the recruiter sent over to the company I was applying and it became a huge mess (paragraphs were overlayed on each other, text was cropped at the side of the page, half blank pages, etc. - just so they could add their logo to every page), so I sometimes also ask the recruiters if they usually modify CVs and then send over the .rtf version as well. They never complained that it's not .doc. (Also because of this as an interviewer I try not to give too much attention to the design of the CVs, especially if it comes through recruiters)