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.
Note that some recruiters although they 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