Perform Query Then Insert Output Into SQL "IN" Statement

Hello All,

This is driving me nuts. I have a simple query: "SELECT District From WorkLocations WHERE A = 1". I need to take the output of that query, which consists of about 12 work locations, and then use that data to input it into a SQL query using $strWhereClause on the List page of a project. How do I form the first query to get the output I need consisting of multiple work locations and then put it in the format for the "IN" clause so it looks like SELECT * FROM Table WHERE District IN ('D1','D2','D3','D4','D5').....D1-D5 represent the output from the first query.

Thanks again in advance.

Brian