Xbox Activation of Mindcraft

Without the receipt that contains the code you're most likely unable to re-obtain a code for the game. The receipt would act as the proof of purchase and in most cases without a definitive proof of purchase that's either physical or linked to the person's/child's
account it would most likely be rendered impossible to get another code without having to buy one.

You could try to see if the Xbox Support troubleshooter over codes could replace it.

https://support.xbox.com/en-US/billing/codes/digital-code-solution

Other than that calling Target's customer support office may be a good course of action.

https://contactus.target.com/ContactUs

Hmmm Mindcraft on the xbox 365... now that sounds interesting

He's confused lol. He enjoys Super Mario Bro games, Sonic etc. But he's starting to branch out to Mindcraft. I wish they made Mindcraft and the new Star Wars Battlefront for the Wii U. His friends all have the wii u and/or xbox 360.

invit me to a mindcraft server

I play Mindcraft. Add me.