Sorry for the LONG message, but I was just trying to provide the necessary information!
The good news is that one of the items you mentioned (<target "mytarget" if="property"> means the target won't be executed if the property isn't set) was the ticket and lets me accomplish the goal of getting rid of the file on the file system.
I was actually already using the "if", but was making it too difficult by having it check for the existence of a file vs a property that was set. Live and learn. Ant/programming is fairly new to me, so you may see me visiting the saloon once in awhile - if not for help maybe a drink!
Thanks again for your help,