The format of the execute form of MODCB is:
[label]
MODCB
[{ACB|EXLST|RPL}=address] ,keyword={address|name|abs expression|option},... ,MF=(E,address)
Requirement: If the execute form of MODCB is used and EXLST is used as a keyword to be processed, the block must be identified by ACB=.