No matter what, the command you are trying to run is going to show up in the process list. ps parses the /proc information and formats it nicely and will show everything running no matter what you might do in perl (assuming you don't use hacked versions of ps and top).

The only way to keep command arguments from showing is to use open() and pipe your arguments to it through STDIN. There might be some potential for obfuscation, but that's about it.