The method of trimming a prefix is determined by how the prefix is defined.
The simplest way is for the prefix code and the remaining data to be separated by a unique character, say ':'. Then you can use the "scan" function as in below
trimmed = scan (prefixed, 2, ':');
trimmed = scan (prefixed, -1, ':' );
A more complicated method would be that the prefix is required to be lower case and the first character of the real data is capitalized. Then you would have to use a do loop (do while or do until), the substr function and either the ANYLOWER or ANYUPPER function to find the beginning of the real, non-prefixed, data.