Enterprise Developer and RM/COBOL differ in the way that they allow you to select records from and indexed organization file.

RM/COBOL allows a WHILE LIKE filter in the START statement. The filter is passed to the file manager and only records that match the filter are returned to the COBOL program for processing. Enterprise Developer does not support such a filtering mechanism. The COBOL program must retrieve all the records and filter them in the program, which is less efficient, but at least emulates the RM/COBOL feature. The C$REGEXP library routine can be used to apply a regular expression filter similar to what the WHILE LIKE phrase in RM/COBOL would apply in the file manager.