sql convert function

greetings

I used convert function in sql server with no problem, but when i try to use in in vb6 for my quiry it does not recognize the convert function

vdate=cdate("30/01/2011")
rst.open "Select * from mytable where docdate=" & convert(datetime,vDate, 102)

this suppose to filter the rst with docdate= vdate only

note that , docdate(datetime,null)

this gives an error :
compile error:
Sub or Function not Defined

I am not sure now if the CONVERT function of sql server is supported in VB6

rgds
cyrus