Working on LVP (Low Volatage Mode = no need for 12V) and release the code in less than one hour!
PS : just received my 16F876A, so I'm gonna try! 
EDIT : ARRRRRHHHHH having problemes with LVP :s Doesn't work, actually 16F876 don't work like 16F628, that's a bit more complicated than ithought. Anybody who want to help is welcome!