The user exit is passed the default remote SYSID that CICS® works out by using the rules that are shown in Two ways to implement DPL in your application program.
If the default SYSID is that of the local SYSID, a null string is passed to the user exit.
The information that is passed to the dynamic distributed program link exit in the user exit specific structure can be changed so that the distributed program link request can be rerouted.
If you want to reroute the program link request to the local system, leave the SYSID blank or set it to the local SYSID, which is passed in by using the parameter UE_Dpllclsys.