First off, I've checked the initline.sqf script and its working fine. The problem you are running into, I think, is a syntax error. If you are surrounding code with "" then any code that requires "" within this statement must use double "" "" or you can use '' instead, as each ' is the same as "".
So your code in the initline script needs to look like this: _name setVehicleInit "nul = [BLU_1Plt_RF1, 'Mobile1'] spawn compile preprocessFileLineNumbers 'setPosMarker.sqf'";