Which char is NOT in result MD5Digest

[Claudi Cornaz]

Hi all you wizards,

Is there a character that won't be in the result of the MD5Digest?

I try to ceate a list of control id's a comma and the MD5Digest of the  
script of that control.
Unfortunatly the cr character can be part of the resulting MD5 thus  
throwing of my lines with a part of the MD5.

Now of course I can replace the cr but which char to use? I need one  
that for sure isn't returned by the MD5.
Or differently: how can I keep my control id's and corresponding MD5  
seperated from each other in a list, to get at each in turn?

TIA
  Claudi