If I understand you correctly, you want to have other fields of the IPTC info filled according to the shooter (serial number).
If I remember correctly you could use multiple code replacement with variables.
You would do something like
in your CR text file:
// serial - photographer - city - copyright (the // at the start denotes this is just a comment line)
123456 John Doe Los Angeles John Doe, Los Angeles Newspaper
987654 Jane Doe New York Jane Doe, New York Newspaper
(remember that the fields in the CR file need to be separated by TABs!)
And in the IPTC stationery, you would use \{snum}#2\ for Photographer field, \{snum}#3\ for City field, and \{snum}#4\ for Copyright field.
The \ character is your Code replacement delimiter character (as set in CR settings), the #2 in the CR tells it to use SECOND field from the CR text file. Et cetera.
It is actually in the pdf manual, you just have to put the info from two sections on CR togerther ;-)
In the whole, the code replacement feature is really great for all of this and more. With the additions of support for variables and multiple replacements, you can work wonders with it.