UserID in Crystal Reports

I'd like to put into my Crystal Reports the ID of
currently logged user. I was searching through archive of group and
found such thing:

"...Calc_RptUserID is what you're looking for. It's under one of the
tables, seems to be semi-random on the placement. POform has it under
PODetail, ARForm has it under INVCDTL and Packing Slip has it under
SHIPHEAD. ..."

I wasn't able to find those fields in Vantage Object Explorer neither
in PODetail nor in ARForm.

I found in UI Objects the UserName and UserID as Session Variables, but
I don't know how to use that information in Crystal Reports. Is it any
way to pass those information to CR, or maybe there is some other way
to put UserID in CR?

My version of Vantage is 8.03.305H

Greg