U can do that by copy paste feature inside PRO ATC.
Just copy ur route from PFPX and put it in notepad, then remove the SID and STAR (cuz u will choose them inside pro ATC) and put the icao's of both destination & arrival.then copy the modified route.
Go to pro atc and in the flightplans click right mouse and select copy paste, put ur modified route and then select the sid & star and tgen ur PFPX route set correctly inside pro atc. Thats it simply.