Get info from email using Applescript

I'm fairly new to Applescript and was looking for a way to check unread messages in my Mail Inbox for information in the form of dimensions. So, when someone sends an email containing, for example, "26x12x8", it will pull the numbers to then plug into a spreadsheet.

If anyone can help point me in the right direction on how to activate Mail, check an unread message for dimensions in the body, and pull that information into spreadsheet cells, it'd be greatly appreciated. Thank you!