Greetings Brenda,
This is a weakness within Lawson. The replacement function does not work with RQC (which would be ideal). There is no easy means to identify replacement items. We handle this one of two ways:
1) Replace the IC11 record with the new item (change IC11, IC12, PO13, PO25/CM). This should only be done with item replacements that are, for all intents and purposes, considered exact replacements.
2) Inactivate the old item. Use the Description field to reference the new item (new IC11 record).
It isn't ideal, but I haven't found a better means to accomplish this.