Friends- How to allow a private function of one class to be called from another class

      I have a piece of machine control code running under Win95 (will someday run under WinNT when it supports the DAQ hardware) written with VC++ 4.x. The main initialization/splash dialog routine does all the rudimentary hardware setup, registry reads, database table reads, etc. But, there is a debug option that can be enabled from an environment var that will skip the machine hardware setup and will bypass all future calls to the hardware to allow the software to be run on a desktop w/o the machine.
         The problem comes in b/c there is a button I have given the user to allow them to toggle the system out of Debug Mode and into Run Mode. Well, if the system started in debug mode, the hardware was never initialized so there will be bunches of errors. Right now I have the hardware init code duplicated in two places (hard to maintain). How can I use the C++ Friend operator to allow the button click procedure in another class to access the hardware init procedure in the startup routine? Should I use another method? The online docs are vague in the friend operator usage. I tinkered with it, but was never successful.Thanks. Code is available upon request...