WordPress MU

The default page home.php is under /themes/home/ directory. Instead of creating a About page from within ADMIN function, I like to create it as a regular php page just like home.php. My home.php code is like
<?php get_header(); ?>
home contents goes here
<?php get_footer(); ?>
I'd like to have the about.php similar to it
<?php get_header(); ?>
Aboutcontents goes here
<?php get_footer(); ?>

First of all can I do this? Is so, where should I put the about.php so from header.php I can link to it.

Thanks

In the directory of whatever theme you want to use for the main blog, be it /themes/home/ or if you switch, to whatever one you switch to.

Thanks for the reply.
I tried what you said. But I got this error

Fatal error: Unknown function: get_header() in /home/myname/public_html/wp-inst/wp-content/themes/home_new/about.php on line 1

Thanks

Using pagetemplate.php and creating about page within ADMIN function works fine for me.