Use Same Customer-Material Record for Many Other Customers

Good afternoon Gurus, Senseis, and Soothe-sayers:

Many blessings on you all.

My client wants to apply the same customer-material record to many other KUNNRs.  So for example, say you create a Cust-Matl Info Record (VD51) KDMAT XXXXXX18578 corresponding to MATNR 401683 for KUNNR 33648.

Now they want to quickly extend this Info Record to multiple KUNNRs 33692, 33547, 33384, 33596, etc.  They do not use Customer Hierarchies.

The business example is that they sell products to Walmarts in New Jersey.  Then they add new Walmart KUNNRs for Pennsylvania.  Instead of laboriously creating new Cust-Matl Info Records for all the KUNNRs, how can the same record be quickly and easily extended or copied to other KUNNRs?

Would it be acceptable to copy such from table KNMT to excel, modify as necessary and then re-upload via WIN Shuttle or LSMW?