hi Mike,
you try to do it the wrong way. You should not try to modify your SQL-Code from outside. You can define input parameters in SQL-Procedures too.
ALTER PROCEDURE dbo.DateRange
@inFromDate datetime,
@inToDate datetime
as
set nocount on;
SELECT FirstName, LastName, DateofBirth
FROM Table1
WHERE DateofBirth BETWEEN @inFromDate AND @inToDate
ORDER BY DateofBirth
RETURN
Know you just have to find out how to pass over the date values from Visual Basic to the procedure. As this is nothing unusual you should find your way trough.