Don't know if this can be done, but here goes. Given the below structure and example data:

Grpid  Grpver   Ref    Len Descriptio

ODDE      1     POLNO  25  Policy Number
ODDE      2     POLNO  25  Policy Number
ODDE      3     POLNO  25  Policy Number
ODDT            DDCDL   3  Code Length
ODDT      1     DDCDL   3  Code Length
ODDT      2     DDCDL   4  Code Length
6SBC            CANCL   2  Cancel Days
6SBC      1     CANCL   2  Cancel Days
6SBC      2     CANCL   3  Cancel Days

I want to select distinct records for the ref field but I always want the highest Grpid+Grpver value. So in the above example the query result would be 3 records:

ODDE      3     POLNO  25  Policy Number
ODDT      2     DDCDL   4  Code Length
6SBC      2     CANCL   3  Cancel Days

Because ODDE 3 and ODDT 2 and 6SBC 2 are the highest grpver's for each grpid. Can this be done?