PHP extension and the open file

Hi, I've coded an extension for php in C. It's based on an other project called "redtemplate" write in C too. Redtemplate is a template system likes clearsilver. In my extension, there are the function rd_display($file) which call redtemplate_parse() which open the $file with open or fopen (lex/yacc do this job). My problem is that extension doesn't work in browser. I mean, in console, "php index.php" work but in browser, on the same php file, i have this message : Fatal error: File 'themes/lanteam/main.html' not found ! ... I think the problem is where php is executed in apache. What do i do to solve this problem ? homer242.