when the shipper (packlist) is created an invoice ID is applied by the system
SHIPPER.INVOICE_ID

an example might be  SHIPPER.INVOICE_ID 164331 on SHIPPER.PACKLIST_ID PK250999

additionally  users are allowed on the receivables side to manually create invoices without having created a shipper.  this is how we create credit memos
our users will take the an Existing Invoice_ID to which a credit memo is related to and add cm to the end
manually creating a new Receivables.Invoice_ID of 164331cm in the system

so both 164331 & 164331cm exist on the Receivables side, however the cm is not linked in any way to the Shipper db

Is there a way to link SHIPPER.INVOICE_ID and RECEIVABLE.INVOICE_ID based only on the first 6 characters so that RECEIVABLE.INVOICE_ID 164331 & 164331cm both link back to SHIPPER.INVOICE_ID 164331

I want to LINK the fields in the table based on the left 6 characters