SAP ABAP Unicode check error fix

A Unicode check (UCCHECK) returns an error on this statement:

"DO 12 TIMES VARYING HEX FROM H_KUMU NEXT H_KUMU+1."

It says "HEX" and "H_KUMU" are not type compatible. "HEX" is type x, "H_KUMU" is RAW.

How do I fix this?

DO ... VARYING is obsolete in Unicode programs. Use ASSIGN ... INCREMENT ... TO ... CASTING RANGE ...