A family of Microsoft relational database management systems designed for ease of use.
You'll need to explicitly populate the parameters. Try
Dim rs As DAO.Recordset
Dim qd As DAO.Querydef
Dim prm As Parameter
Set qd = CurrentDb.QueryDefs("QueryName")
For Each prm In qd.Parameters
prm.Value = Eval(prm.Name)
Next prm
Set rs = qd.OpenRecordset(dbOpenDynaset)