Automatic Reminder email from Excel 2013 in Windows 7 pc

Hello Everyone!

This is my first post here. I am using Excel 2013 OS win 7. I need your help in developing a mechanism to send an automated outlook mail, when the due date of a project is nearing 3 hours, 2 hours & 1 hour away from the current date & time. The script should preferably run automatically every time the PC is running when the excel file is open.

In the attached excel file, An email should go of to -email address (Col. F), with subject "number (Col. B) is due on Due date and time (Col. E)", and body "Dear Name(Col. F), please finish your project asap".

Also, the script should put a check mark on Reminder sent column (Col. G) after the mail is sent, the script should also check if the value of the cell is blank before sending email.

I have scoured the forum for similar problems, and although I found a number of of threads,I am not proficient enough in VBA to modify them to my needs.

I'd really appreciate any help,