Hi Theo:
I am pretty sure I have seen the footage you refer to on a DVD 'The Archive Collection - German Night Flyers' published by Artsmagic. This DVD contains several minutes of film obviously lifted from Die Deutsche Wochenschau, which show the tracking of an incoming RAF night raid, Bf 110s taking off, a twin-engine bomber being engaged and shot down, etc. Helmut Lent features in the vision. The commentary and the vision suggests the film dates from around early 1942 (at a best guess).
The DVD is available for purchase e.g.
https://www.amazon.com/War-Archive-G.../dp/B000F48DBY. I came across a complete copy of the DVD on You Tube, but was reluctant to post the link, as I am unsure how copyright laws would apply. Anyway, you can simply search using the term 'German War Files - German Night Flyers - YouTube'. See several minutes of vision starting at the 29.00 minute mark.
There is also an earlier thread which also seems relevant to your search:
http://forum.12oclockhigh.net/showthread.php?t=7207
Hope that helps
Don W