How to edit post to add a command line at .nc

[ekit]

hi all,

I am new in programming. The machine i use is fanuc 0imb control with high precission function G5.1. I need to edit the generated nc file to add two lines of G5.1Q1 at beggining and Q0 at the end every time.
Is there a way to edit the MasterCam 9.1 post file (eg. MPfan.pst ) to add the lines automatically?
How can achive it?
Is there anyother Cam software you know can achive this? How to do?

Thanks a lot.