Using variables in WordPress page

Hi,

I’m trying to insert variables into a WordPress page.
As far as I know there’s no possibility to put PHP code into a WordPress page.
I found a plugin called “Allow PHP in post and pages” which allows inserting code into a page.

That’s exactly what I’m trying to do:
I’d like to create a page for specific users, which need to log in first.
The page should be like “Welcome [first name] [last name]”. The user information should be taken directly from the user profile info.

Is there a way to put that in the page?

Thanx!