Dear SAP expert,
We decided to replace our current J.D.Edwards ERP system (JDE) by SAP. 
Beside other things we now we need to migrate about 400000 material masters from JDE to SAP.
Initial situation
JDE material masters have 3 different unique item numbers. A so called short, a long and a catalog item number. The short number is used for internal table references. We use only the long and catalog number and these numbers can be different. The long item number is our leading item number and it is used internally in BOMs, routings, work orders, etc. The catalog item number is printed in our product catalog and communicated to 3rd party business partners like customers and vendors. Catalog numbers are used in purchase and sales orders.
As we need to keep our leading item number, the long item number will become the SAP material number.
Problem 
We also need to keep our catalog number but a text field in the material master with the catalog number is not the solution. We need the same functionality like the SAP material number. It must be possible to enter those article numbers in sales orders.
Question 
How and where to maintain a second (catalog article) number in the SAP system?
I know that you can set-up item number cross-references between vendor respectively customer item numbers and SAP material numbers. On supplier side it should not be a problem to set-up item number cross references because the number of similar articles that are purchased from different vendors is limited. We need usually only one item cross-reference per item and vendor.
On customer side it is different. About 60000 standard catalog articles can be sold to each of our customers. That means to set-up a cross-reference between all catalog articles and all customers can’t be a solution.
As I have no idea about the possibilities in SAP I need to ask YOU for help. Is it possible to set-up some kind of a “dummy” customer, so that we need only one item cross-reference per article and dummy customer?
Many thanks in advance.