Whats the proper way to use a php stylesheet in a wordpress theme? [duplicate]

Not sure if that’s what you need, but take a look.

// Can be put into function.php

if ( !is_admin() ) { 
    add_action( "wp_enqueue_scripts", "enqueue_scripts", 11 ); 
}
function enqueue_scripts() {

    // Theme CSS (style.css)
    wp_enqueue_style( 'style-file', get_template_directory_uri() . '/style.css',false,'1.0','all' );

    // JS
    wp_register_script( 'script', get_template_directory_uri() . '/your-script.js', array('jquery') );
    wp_enqueue_script( 'script' );

}

Or use …

// Used to include PHP
include_once(TEMPLATEPATH . 'script.php');

Sometimes it helps to also tell the .htaccess file how files should be handled. Throw this in your .htaccess file.

# handler for phpsuexec..
<FilesMatch "\.(css|style)$">
 SetHandler application/x-httpd-php
</FilesMatch>