What way could I do this

[Andreas]

Hmm ...

PHP Code:

<?php
 $foobar = 'Foo Bar';
 $templates['header'] = '<table width="100%" class="mytable"><tr><td>$foobar</td></tr></table>';
 $compiled_header_template = str_replace('\\\\$', '\\$', addslashes($templates['header']));
 eval('$header = "' . $compiled_header_template . '";');
 echo $header; 
?>

Output

<table width="100%" class="mytable"><tr><td>Foo Bar</td></tr></table>

Seems to work for me.