If memory serves me correct you can, I think you then just need to make a 'Directory Junction/Symbolic Link' (whatever it's called) or a registry edit to get everything happening. Again if I recall correctly (may have been another product) there was been talk about having the ability for the Rapture Pro substitution thing, don't think it is available at present, or indeed if it ever will.
[Edit] With Rapture Pro, I think all the stuff from Rapture and Dim Pro ends up (copies?) in the directory where your Rapture Pro stuff is, perhaps then there is no need for the originals any longer if you just use from Rapture Pro, but you would still have the 'old project replacement' issue.