The software could be any graphic editing program that gives you an x,y position while editing. I use Photoshop and it can give me these positiions. I'm not sure what other editing software does the same thing, but perhaps someone who uses something other than Photoshop could tell us.
No problem on the quick response. I'm here quite often (eating up Neal's bandwidth
reading everything I can get my eyes on) and it just happened that I had just recently done exactly what you wanted to do, so it was fresh in my mind (or what precious little is left of it:p ).