Left function ASP access database

Hello everybody,
i have a problem with the left function.
i give in input btn_serial a serial number which has 10 digits like 1234567890 and search
in access col_serial serial numbers which starts with with the same first 4 digits of number entered in btn_serial.
my target is to view all serial numbers in col_serial which satarts  with 1234 like in the example on top.
example of data sent by <input name="btn_serial" value="1234567890">
result should be
1234567890
1234098765
1234645412
1234809082
1234543567
1234236788
etc.

here is my code
and 1000x thanks for your help
Rafal

<%@LANGUAGE="VBSCRIPT"%><%
%><!--#include file="join.asp" --><%
if request.querystring("sort")<>"" then
sort=request.querystring("sort")
else
sort="col_serial"
end if

Dim rsbiz
Dim rsbiz_numRows
Set rsbiz = Server.CreateObject("ADODB.Recordset")
rsbiz.ActiveConnection = MM_join_STRING
rsbiz.Source = "SELECT * FROM tbl_support WHERE col_brand='" &request("btn_brand") & "' AND col_modell='" &request("btn_modell") & "' AND (Left([col_serial],4))='" &request(Left([btn_serial],4)) & "'" '" &sort & "'
rsbiz.CursorType = 0
rsbiz.CursorLocation = 2
rsbiz.LockType = 3
rsbiz.Open()
rsbiz_numRows = 0
%>