[Typo3] how do I include a link to an extension file in the header

[Stephane Schitter]

Hello,

I am trying to build an extension that uses ADxMenu 
(http://www.aplus.co.yu/adxmenu/intro/).

As they suggest, I would like to include the following code in the 
generated page:

<style type="text/css" media="all">
	body { behavior:url("HTCPATH/ADxMenu.htc"); }
</style>

As ADxMenu is embedded in my extension, I need to reference the files 
with an EXT:myext prefix. I originally thought to add this using a code 
similar to this:

in constants:
    adxmenu = EXT:myext/ADxMenu/ADxMenu.htc

in setup:
    page.headerData.10 = TEXT
    page.headerData.10.value = <style type="text/css" media="all">body { 
behavior:url("{$adxmenu}"); } </style>

but this fails, as it adds the following code to the page (not 
substituting EXT:myext with the correct path):

<style type="text/css" media="all">body { behavior:url("EXT:zenlight_tmpl/ADxMmenu/ADxMenu.htc"); } </style>

And I cannot define this either:
    page.headerData.10 = FILE
    page.headerData.10.file = EXT:myext/AdxMenu/ADxMenu.htc

as this would want to *include* the contents of the file, and not create 
a reference to it.

Could anyone please provide a hint on how to achieve this ?

Thanks !
Stephane