AFAIK, there isn't. If you know the structure of the other site, you could use Server.MapPath to get the path of the current site, and then use replace to change the staring path of the file.
Pretty messy, but it might work.
What are your requirements for this functionality? What are you using it for?
Imar
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Imar Spaanjaars
Everyone is unique, except for me.