Question : Web query - parameter to refer to cell in excel

Hi - i'm super beginner here so this question might be stupid easy.

I am working in excel trying to bring in data via a web query.  It works as desired if I use the following:

http://dssql01/getdata.asp?p_sp=r_GetMembershipByNetwork&p_parm1='09.01.2008'

However I want the last bit, '09.01.2008' to refer to a cell in excel (in the same workbook) so that the user can just input a date and the query refreshes.  How would I do this?  All of my attempts so far in referring to the cell yeilds "error converting data type nvarchar to datetime."  (And is the stored procedure necessary in order to answer the question?  I obviously did not write it but can provide it.)

THANK YOU

Answer : Web query - parameter to refer to cell in excel

Hey - thanks so much, still not working, same error.  I'm going to check with the guy who wrote the stored procedure to see if there are some oddball restrictions with our server or something...but I won't see him til Monday.  Thanks - and I'll check back in next week to either ask more or award points...hopefully the latter.