use like:

Set rs = execute_query(conn, "SELECT custid, custname FROM customers WHERE (somefield > ?) AND (someotherfield < ?)", Array(someValue, someOtherValue));

where conn is a "ADODB.Connection"

Function create_variant_input_parameter(command, name, value)
  Dim param
  ' 12 -> adVariant
  ' 1 -> adParamInput
  Set param = command.CreateParameter(name, 12, 1, 0, value)  
  Set create_variant_input_parameter = param
End Function

Function execute_query(connection, querytext, parameters)
  Dim cmd, i, rs
  Set cmd = Server.CreateObject("ADODB.Command")
  cmd.CommandText = querytext
  ' 1 -> adCmdText
  cmd.CommandType = 1
  For i = 0 To UBound(parameters)
    cmd.Parameters.Append(create_variant_input_parameter(cmd, "", parameters(i)))    
  Next
  Set cmd.ActiveConnection = connection 
  Set rs = cmd.Execute()
  Set execute_query = rs
End Function