Merging two lists together using VBA program

Hi,

I have a worksheet with two separate lists. I need to merge the two lists to form one list so it contains the states in a given region together (i.e. western states together etc.). How can I write a VBA program to do that.

Attached is the workbook:
States.xlsx

Thanks

One way, if you're willing to place "region identifiers" in front of the states.
The UDF can be found in Module 1.