Most of this has nothing to do with electrons (but with hadrons and muons), except IONFLUCT that switches off ionization fluctuations for electrons too.
To your purpose, you should suppress in addition bremsstrahlung fluctuations, as already explained in this forum.
By scoring BEAMPART (or ELECTRON) fluence with USRBIN (no need to go through ENERGY deposition scoring coupled to AUXSCORE), you will get then the CSDA range.