[link|http://www.iknowmymusic.co.uk/archive/quiz_45_answers.html|Ellen Foley], at least if you believe that quiz. (I dunno myself.)
I haven't found any video other than [link|http://www.amazon.com/exec/obidos/tg/detail/-/B00003XAMG/qid%3D1101703177/002-2991523-4539269|this] DVD at Amazon. PbtDL is on there, but I don't know if she did the duet with him (nor whether it's close enough to what you're looking for). It's $9.99.
HTH.
Cheers,
Scott.