Query SQL Server from Excel with parameters linked to cells
I have found a driver that I can install on a PC that does not have SQL Server installed on it and it makes Excel's data connections connect to SQL Server with cell linked parameters that are dates. The install can be found here: http://www.microsoft.com/en-us/download/details.aspx?id=36434

You then need to change the driver in your connection string to look like:

DRIVER=ODBC Driver 11 for SQL Server;SERVER=blabla.yadayada.eu-west-1.rds.amazonaws.com;UID=MyUserID;PWD=MrPasswordMan;APP=Microsoft Office 2013;WSID=COMPUTER-NAME;