I came across this query several times to how to find the spool request number when you know the Output Type. Untill when I require the same I didn't try to think deep on it.So, I thought of putting the solution here for others also.
Whenever a print is issued, there is a corresponding entry in the table NAST along with that there is a entry in the table CMFP also. This entry is stored as an error message management og type I.
See SDN Article





