Date Time Convert In A Sp Value

I need to create a sp for sql 2000 to run with Crystal 7. (No I can't upgrade the crystal). The user wants the calendar prompt to be issues when Crystal with the calendar function. The problem is that if I define the sp var to be passed in as a datetime, crystal wants the hh mm ss also. if I issue it as a varchar(10) and convert it in my select it won't bring up the calendar control. Never tried this but I am guessing you can't do a convert on a var you feed from an sp like below

create procedure checkdate @date convert(varchar(10),@date,101)
as
select * from patient_medication where create_timestamp > @date

Any ideas?