I'm using SQL Server 2008.

To get the script to work for decimal numbers like 35.12, I had to change

when isnumeric(ExtRef) = 1 then ExtRef

to

when isnumeric(ExtRef) = 1 then cast(ExtRef as decimal)

After I made that change, I was able find the problem that decimal data with dollar signs are considered numeric but can't be cast as decimals.

Jim