Cascading Drop Down Control & DataSet using MS Access

Hi,
I'm after some help with the following. I am creating a cascading drop down control for use with some drop down lists. They are filled using datasets which connect to a MS Access database. The first dataset was no problem however now I need to create the second which contains a where clause using a passed parameter (ie the selected value from the first drop down). In examples I have seen on the web the @ symbol is used eg WHERE fubar = @varname
When I try to execute this in the query builder in VS2008 I get two errors:
Error in WHERE clause near '@'.
Unable to parse query text. 
Followed by:
Executed SQL Statement: SELECT DISTINCT tbl_frame.frame_name, tbl_product.frame, tbl_product.model
FROM            (tbl_product INNER JOIN
 & ...