Please include technical information, such as the version of Crystal, it's extremely important as the functionality differes greatly during the past 2 years.
In general you don't write queries using parameters, you write the Record Selection Formula to allow for filtering on the database.
An example might be (report->Edit Selection Formula->Record):
(
{table.date} > {?MyDateParm}
)
and
(
{table.Someid} = {?MyIDParm}
)
etc.
Hopefully this is what you are intending, if not, please include technical information in your posts, such as Crystal and database version.
-k