Оригинал.
… appoints as Special Attorney X (данные физ. лица)
so that in the name and on behalf of the Company “Y” he can finalize the contract with the Company “Z”.

The appointed attorney is therefore authorized to intervene in the Contract agreeing terms and conditions, and in any case to take any action, ***even otherwise qualified***, to perform the Contract with particular reference to (и дальше перечисляются конкретные полномочия):
- regulation of relations with the Client;
- definition of accounting reports and billing…

Под перечнем полномочий фраза:
All the above-mentioned will be accomplished free of charge, ***exhaustive in its single context***, and with the obligation to render account hereof.

Заранее благодарю за помощь