Call a page from the theme directly

[Domi]

Hi,

how, in my php code, I can call a page directly (without using the admin page control panel) ?
ie: have a page in my theme : under-construction.php but when I calll it (somewhere else in my code) like this :

PHP Code:

<a href="<?php get_theme_url(); ?>/under-construction.php">Consulting</a> 


I get "you cannot load this page directly." which is normal and what I can expect but how to load it 'normally' like if I use it thru a page ? is there any way ?

thanks in advance,
Domi.