How do I order a union-part with letters before a union-part with numbers in MS SQL Server?

I have a Union between two concatenations (columns concatenated into one column in each union-part). The first union-part contains only letters. The second union-part contains only digits/numbers.

When executing the query, I get the results ordered by the second union-part with only digits/numbers before the first union-part with only letters.

How do I change this so that the first union-part with letters is ordered first, before the second union-part with digits/numbers?

Open in new window