What exactly are you trying to accomplish?
Knowing that, it would be easier to give you a solution.
You can use CPYSPLF to a flat file and then use CPYF to put it back into a spool file, but that may not be the best solution for you.
There are a few choices
1. A cl program can do
1.1 an OPNQRYF to select the one persons records
1.2 an OVRPRF can set the SPLFOWN – although we usually use seperate outq’s
1.3 call the invoice processing program
1.4 clof the qryf
1.6 go back to 1.1 for next user
2. The invoice processing program can be changed with the printer file set to usropn
2.1 an OVRPRF can set the SPLFOWN – although we usually use seperate outq’s
2.2 open the printer file
2.3 process records for that user
2.4 close the printer file
2.6 goto 2.1
3. If the spool file is not *AFPDS
3.1 use CPYSPLF to copy it to a flat file with *FCFC
3.2 have a program read through the file picking each record for user1
3.3 write each record for user1 to a second flat file
3.4 use cpyf to copy the spool file to qsysprt
3.5 repeat steps 3.3-3.5 for each user
ROBOT reports can break down the spoolfile, if there is something on the page to determine the routing.