in this case you can use the %%LIBMEMSYM autoedit variable.
You must create one text file in a directory reside on the Control-M Server. This file must be accessible to CONTROL-M/Server.
Put in this file your variable and value.
This variable enables you to create a central file containing AutoEdit assignment statements that can be read by many job processing definitions.
See CONTROL-M Job Parameter and Variable Reference Guide for more details or you can find also answers in this forum.