[AccessD] Recordset based on query

I keep thinking this should be fairly simple.

I need to check through the results in a query and calculate results from 
them. The code I am using starts with:

Dim rsPopulateQtyBoxes As Recordset
     Set rsPopulateQtyBoxes = New ADODB.Recordset
     rsPopulateQtyBoxes.ActiveConnection = CurrentProject.Connection

     rsPopulateQtyBoxes.Open qryHire_New_Rentals_Extend, , adOpenKeyset, 
adLockOptimistic, adCmdUnknown

When I try to run the code I get this error message:

[]


Thanks in advance for any help offered

David