TSQL Syntax help

[MasterPO]

Good morning all...
I need help with the syntax for a Select statement.

Table = AROPNFIL
Fields = Doc_Type, Apply_To_No, Reference

I want to select the Doc_Type and (when Reference field is Numeric, choose Reference field, else choose Apply_To_No field).

All my attempts at 'If...then' and 'Case When IsNumeric...' have failed! Help!

 

[JohnDTampaBay]

How does this work?

SELECT Doc_Type
  , CASE IsNumeric(Reference)
       WHEN 1 THEN Reference
       ELSE Apply_To_No
    END AS Field2
FROM AROPNFIL

--Angel
-----------------------------------
Every time I lose my mind, I wonder
if it's really worth finding.