how to add commands

[Rizwan Khan]

Hi
I wanted to know how i can add custom command on FC4 box so that i
should be able to execute them from command line. I just installed IBM
PurifyPlus and they suggested me run your command thorough the
following command:
% purify cc -g hello_world.c

but its gving me messge that purify command not found,

Thanks
-- 
Muhammad R!zwän Khän