RE: Item number is a combination of vendor#-item#. Linking no series relationships. Business Central.
First, I don't recommend what you are doing. On an Item Card you have a field for Vendor No and a field for Vendor Item No. There is no need to build it into your Item's No.
With that out of the way, you would want to use the main Item No. series and establish 200+ relationships to it. When you are entering a new Item you would use the ellipses or a Data Template to select which series to number the Item. This is going to open the door for human error and a lot of renumbering of Items (or delete and re-enter).
You should be able to use a Config Package with three tables (308 - No. Series, 309 - No. Series Lines, and 310 - No. Series Relationship) to import your records.
Again, I strongly encourage you NOT to do what you are thinking of doing.
