Calculate attempt column values based on given condition

userID--- ansID --- objid------- testype ---------------- Date--------------- attempt
1 --- ---- 1234 ------ 1 ------ ConceptTest ------- 1/12/2013 12:12:01------- 1
1 ------- 123445--- - 1 ------ ConceptTest-------- 1/12/2013 12:12:01 ------ 1
1---- --- 123445 -----1 ------ ConceptTest ------- 1/12/2013 12:12:02------- 2
1------- 123445 ----- 2 ------ ConceptTest-------- 1/12/2013 12:12:02------- 1
2 ------ 123445------ 2------ ConceptTest ---------1/12/2013 12:12:02------- 1
2 -------2456-------- 2------- ConceptTest-------- 1/12/2013 12:12:03------- 2

If the attempted date changes in (MM/DD/YYY HH24:MI:SS) SS from previous record but the userid, testype, objid remains the same then the counter should be increment by one else previous value should be used
If the any of userid, testype, objid changes from the previous record then the counter should be set to 1 again and repeat

Please any one help me....