Another SQL Question

Given the following data:
FISCAL CONTROL SOURCE SEQ
YEAR GROUP CODE #
2,007 1 AP 0
2,007 1 AP 0
2,007 1 AP 0
2,007 1 JE 0
2,007 1 JE 0
2,007 1 JE 0
2,007 1 CS 0
2,007 1 CS 0
2,007 1 CS 0
2,007 1 CS 0
2,007 1 CS 0
2,007 2 JE 0
2,007 2 JE 0
2,007 2 JE 0
2,007 2 AP 0
2,007 2 AP 0
2,007 2 AP 0
2,007 2 AP 0
2,007 2 AP 0

Is there any method using dynamic SQL (no user defined functions or any other type of sql program), to set a sequence number so that when Year, Control Group or Source Code change, the value will be incremented by 1 starting at 1?
I have tried the Row_Number() Over function, but have not been able to get it to do what I want.

The desired result would be:
FISCAL CONTROL SOURCE SEQ
YEAR GROUP CODE #
2,007 1 AP 1
2,007 1 AP 1
2,007 1 AP 1
2,007 1 JE 2
2,007 1 JE 2
2,007 1 JE 2
2,007 1 CS 3
2,007 1 CS 3
2,007 1 CS 3
2,007 1 CS 3
2,007 1 CS 3
2,007 2 JE 4
2,007 2 JE 4
2,007 2 JE 4
2,007 2 AP 5
2,007 2 AP 5
2,007 2 AP 5
2,007 2 AP 5
2,007 2 AP 5
......

Thanks,

Jeff Young
Sr. Programmer Analyst
IBM -e(logo) server Certified Systems Exper - iSeries Technical Solutions V5R2
IBM Certified Specialist- e(logo) server i5Series Technical Solutions Designer V5R3
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