Is OOBNumber a combobox? The rowsource for a combobox is either a query, table, SQL statement, or a value list.
If the rowsource never changes, just type the SQL into the combobox rowsource property. If not, you can type a query name as the rowsource property and use the code I've provided previously to create the custom query on the fly.
It seems odd to me that you would have the rowsource SQL for a combobox in an unbound textbox. How does the SQL get into the unbound textbox in the first place?
Could you upload a zipped copy of your DB so that I could better understand what you have so far, so that I can make informed suggestions on helping you reach your goals?