Thank you for your quick answer!
The 757 and 767 have a seperate ILS panel on the center pedestal, where you dial in the ILS frequency and course.
Using the HSI_Course parameter displays the value of the VOR course selector on the left side of the MCP.
The only parameter that shows ILS course, even if it's inverted, is VOR_Nav2_Card.
It would be great if you could add the mentioned backward inversion.
Thanks for your efforts.