Trying to convert SQL code to control source of a textbox

Here is the SQL which gives me the correct result.  Am trying to convert it to the control source of a field on a form.  Or maybe it should be the onprint event of the text field?

SELECT Sum([QtyCast]/[Patterns_On]) AS Molds
FROM tblCast LEFT JOIN tblPartsMasters ON tblCast.PartN = tblPartsMasters.Part_No
WHERE (((tblCast.Date) Between #1/1/2012# And #1/7/2012#) AND ((tblPartsMasters.Customer_1)="ABCCompany"))
GROUP BY tblCast.Molder
HAVING (((tblCast.Molder)="Airset Floor"));