Glo Referencing to a CSS file on the main level of the device

[ibu]

I know that there possibilities to use global CSS files with KEPUBs and - in combination with the Calibre plugin "ExtendedKoboDriver" - "kobo_extra.css".

I like to know if you could refer to any css file in the main file system level of the device in the link element.

Something like that:

<link href="kobo:generic.css" rel="stylesheet" type="text/css" />

Thanks.