5
I've been playing with this, and I think I'm on the right track...
By editing multimenu.php and adding
$xoops_module_header .= '<link rel="stylesheet" type="text/css" href="newfile2.css" />';
$xoopsTpl->assign('xoops_module_header', $xoops_module_header);
before
include 'block.php';
the stylesheet link is placed in the head, like it should. You can also extend this to the script that needs to go in the head.
Victory is at hand!
p.s. you need to declare $xoopsTpl and $xoops_module_header as globals, too