That depends on the program that forwards the message. It copies the old message to the new message, but quite often the mailto-link of the original sender is suppressed and just the name is shown.
Some programs add the original message as an attachment; that would be fine in your case. And some, maybe, copy all, including the link.
Nothing you can do about it. It's just not there. All you can do: send your reply to the 2nd party and ask him to forward it to the first party. That might be in his address book, or maybe he still has the original message.