oh my, i don't think can do it by adobe photoshop element (sorry i never tried it cause i never use photoshop element) but maybe for adobe image ready it's quiet possible (i dunno how but it must be there somehow)
or
maybe you could split up the image into pieces and then save it to html so you can add the link for separate piece, anyway is msfn forum support html tag on sig?
or
after you split it, you use bbtag available such as [url=....[img] to the each piece image you want to linked
PS: Photoshop CS is not version 7, CS = 8, CS 2 = 9 and maybe Photoshop 10 will be named Photoshop X