Hi,
I don't know how "2Checkout" is made (because it is not one of our plugins) so I can't say if it is possible.
But for the payment plugins we made, it is possible to specify a url for the confirmation page or to override the "thank you page".
So you can put some PHP code in a specific page where the customer will be redirect at after the payment (url if it was an external payment system ; the "thank you" page if the credit card was asked directly in HikaShop).
So, thanks to it you can redirect the user to your specific and custom dynamic URL.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.