I expect your usual mechanic should be able to diagnose and fix the problem themselves if you are not able to rather than having to use a specialist electrician
I've had 4 different problems with my power windows (on the proton of course)
1. Motor
2. The wire pully thing came off
3. Something else (current problem) - motor works, wire is fine but its not going up straight.. falling to one side all the time
4. The actual switch
The first two times, I've just taken off the door panels and found out straight away what the problem and the last time I was just sick of doing it so I got my mechanic to chekc it out, cost me next to nothing too
PROTONS ROCK!