Different PR number range

Dear all

At my client there are two scenarios of PR creation from maintenance order :

one is for planned services against outline agreement in which PM user will create PO itself.

another is PM user will create PR thru maint. order and give it to commercial dept. & they will make PO.

What I want is the different number range for both the PRs for differentiate the PRs created from orders.

is it possible ?

thanks in advance

regards

vineet