Is there a way to manually add in from the admin panel in the orders module (under a specific customer) a download link of the product they purchased?

I have it currently setup as a checkbox zipfile when placing order, however a few have forgotten to checkmark this box so their download never shows up in the account once payment has been cleared.

or is there a way to automatically select the download checkbox when they select the item to purchase?

ive read and reread the forums till i think my brain is about to explode.

ty in advance for your help

Sin