I highly doubt you could do it with our current switches, I'm pretty sure you'd have to go pillage a junkyard for switches off of a car that does have it. I'm not certain if there'd be compatibility issues as I'd assume that the switches would basically have a "normal" mode, and then if pressed further engage a circut that stays closed until a "breaker" of sorts in them that would open it again after a certain amount of resistance was reached. It's just a matter of how powerful your window motors are compared to those of the original car.
This aside, it may be possible to make up a circut board that accomplishes something like this which you could potentially "piggyback" with your normal system, but it might be a bit silly-complex. and of course you'd need to make seperate "triggers" somehow.
also apparantly I'm going to have to figure out how these window modules work, and figure how to tap into it and add a manual "switch" or 2 that I can possibly blend into my doorpanel.