HI
I assumes that u want to import 2d sketches in to proe and do the programming insted of going 4 3d .
the best way is open ur 2d autocad sketch in proe as a part file (it is possible) and assemble that part to pro/mfg, and do tool paths by u sing trajectory milling,
But by this way u wont get associativity and u wont b able to do any kind of pocketing operation, only contouring.