[AccessD] Assign a control source for the control on Report based on dynamic crosstab query

<Cross posted AccessD Access-L >   
Hi,
I have a report which have crosstab query with dynamic column names for recordsource. So I have to assign the control source for the text boxes on the fly. Something like:
Dim rst As Recordset
    Set db = CurrentDb
    Set rst = db.OpenRecordset("SELECT * FROM  qryCroRealPrPred")
    Me.txtBox1 =  "=" & db.QueryDefs("qryCroRealPrPred").Fields(1).Name & ")"

Where should I put these lines? Or how to recalculate(evaluate) these text boxes(have no succeed with Eval function), because if I put these lines in the Detail Format/Print the text boxes contains only the field names(strings) not the values of the fields(numbers).
Many TIA's
    Ervin