Hi
You need to create the SQL of the query and set the string variable you've declared (sqlstr) to it, something like this
CODE
Dim strSQL As String
Dim qdf As DAO.QueryDef
strSQL = "SELECT Field1, Field2, Field3 FROM SomeTable"
Set qdf = CurrentDb.QueryDefs("AbfrageNew")
qdf.SQL = strSQL
Set qdf = Nothing
Change the SQL statement to your actual SQL