Hello mpcommercial,
The following posts relate to your issue:
(1) pavant
Re: Ability to select shipping carrier for tracking numbers
"I really like this mod and I changed it to work with my 4.1.8 xcart. Here is what I have: ..."
http://forum.x-cart.com/showpost.php?p=179203&postcount=14
(2) balinor
Re: Tracking number in email and on history
"Mod to add the tracking number as a tracking link in the email confirmation that goes out to customers notifying them that the order is complete."
Http://forum.x-cart.com/showpost.php?p=169342&postcount=9
(3) balinor
Add a UPS "track it" button to customer email
"Hello all,
Here is a simple little Template Mod I did to add a "Track it!" button to the email order receipt that redirects to the UPS tracking website instead of just printing the tracking number.
This allows the customer to click the button in the email and automatically go to the UPS tracking page instead of having to login and bring up their order."
http://forum.x-cart.com/showthread.php?t=14498&highlight=Add+a+ups
Best regards