[O] Using non-org files as agenda files?

[Sven Bretfeld]

Dear all 

Is it anyhow possible to use a .tex file as an org-agenda-file? 

This might seem a silly question. The reason is that I stick to auctex
for writing my documents. But it would be nice to be able to insert a
todo item directly at an appropriate place within a tex-file and have it
integrated in org-agenda-view. 

Maybe this can be done by a workaround using ipa.el (in-place
annotations) and setting an orgmode file as ipa-file? Any experiences? 

Thanks

Sven