If you are still registerd (meaning when you open soldat you see your registration name etc) you can easily export it from the registry. If you cant see it when you open soldat,
send an email or a PM on the forums to Michal Marcinkowski (email: michal.marcinkowski@gmail.com), explaining your situation and he will help you out. look in El_Spec's post for email / link to pm
The command to export the regkey is missing some \ though
it should be (i presume you know that you run it in the run box):
regedit /e c:\soldat.reg "HKEY_CURRENT_USER\Software\Soldat"
However on my system (dunno if its where it is supposed to be) the key is located at HKLM so then the command would be
regedit /e c:\soldat.reg "HKEY_LOCAL_MACHINE\Software\Soldat"
if working there should be a file named soldat.reg in your c:\ root folder.
Good luck