Basim,
First, post your question in the main MasterCam forum.
This is NOT a postprocessor issue.
Second, you need to tell us what version of MasterCam you are using.
That way, the appropriate 'expert' can better help you.
I think I found part of the answer you are looking for.
In V9, go Toolpath, Job Setup
In the Toolpath Configuration section UNCHECK the 'Assign tool numbers sequentially' box.
This will keep and post the tool number that is defined in the library.
ObrienDave. MasterCam since V6. Gcode since 1983.
The nose you punch today may belong to the butt you have to kiss tomorrow.