Custom Admin email notification

Hi all! I couldn’t find a thread for this, so here goes:

I would like to adjust the admin email notification for some of my products in the Woocommerce store. I have 4 or 5 products that needs special attention when they are ordered, so I would like the admin email notification to flag them by printing in large red letters something like “ORDER NEEDS MANUAL PROCESSING”. I am not very skilled at php, but I imagine some kind of “if product number 5 or 7 or 22 then” would work.

Can anyone please point me in the right direction?

/Mo