Excel 2007 : Automatic e-mail sending in Excel 2007

I'm new in both Excel 2007 and this Forum, so any help from your side is appreciated.
I have a shared Database like below:
A B C D
1 Ann High 04/01/2012 [email protected]
2 Bill Low 04/15/2012 [email protected]
3 Peter Medium 04/23/2012 [email protected]

I need a code or any way so will result in:
If data in column B is High; then 3 days before date in C the automatic e-mail should be generated and send to the address in D column;
If B is Medium then 2 days before;
If B is Low then 1 day before;

Thank you in advance.

This may help
http://spreadsheetpage.com/index.php...il_from_excel/