Want to change bar.htm/?source=whatever to bar.htm (without trailing slash or query string)

I've spent two hours trying to mess with mod rewrite stuff to no avail.

I think the title pretty much says it all, but to reiterate...

I stupidly set up some URLs (on partner sites, search engines, etc.) a while back that look like this:

http://smilezone.com/foo/bar.htm/?source=overture  and
http://www.smilezone.com/foo/bar.htm/?source=findwhat

I'd now like to have these queries redirected to, for the examples above, to
http://smilezone.com/foo/bar.htm

(with no trailing slash or query string)

Thanks in advance for your quick help on this, and happy early Thanksgiving!

Regards,
Adam

P.S. -- Please note that I'll be gone a couple of days for Thanksgiving; I'll return by Friday and will view comments at that time.  Thanks for your help and your patience :)