No, that isn't possible without the cooperation of both his own Internet provider and the Internet provider of the office. Those are the ones that give it to you.
What he has to to: login to his work via VPN. Then he uses the office IP. The IT staff of the company knows how to set it up. But they might find it too much work, or too expensive or against the company policy. Just ask and see what they say.
okay, so i have a client who wants to change his laptops ip address to his office ip address. he wants to be seen that he is working from his office by appearing with his office ip address. is it possilbe ?

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