Burning a boat loader to micro/pro that is soldered in.

Like a complete idiot, I soldered a micro/pro to a circuit board w/o testing it first. I cannot program it via USB port, it's acting like there is no boot loader.
So the question is: is it possible to hook up and program with an ISP ? I thought I'd be ok since nothing uses the serial lines; but I neglected to check to be sure it had a boot loader... Now I'm trying to just not have to desolder the whole thing..

What do you mean by micro/pro?