Passing parameters through Excel to an Informix DB works through MS Query but fails when returned to Excel due to General Error

Question

I require to query an informix database using parameters and Excel. When the query is executed in Microsoft Query the dataset is fetched and returned succesfully, when I attempt to return to Excel the following error occurs:

> [Informix][Informix ODBC Driver]General Error.

The query is as follows:

SELECT DISTINCT t1.r1, t1.r2, t2.r3, t2.r4 
FROM informix.t1, informix.t2
WHERE t1.r1 = t2.r5 AND ((t2.r3=?) AND (t2.r4 =?))

Hope you can help as I'm new to this.

Thanks in advance