He IS still not in the office.


"still" and "yet" mean something similar, so you don't need them both (although you can keep them both in if you want). Of the two, "still" is much harsher, and therefore the one you definitely want to use in this case. "Yet" doesn't really imply that he should already be there, just that he isn't yet. "Still not in the office" implies that you've been waiting for him to turn up for some time already.

Vielen Dank euch beiden!

und warum danken sie nicht mir, ich hab wörterbuch erfunden

ne isch auch! glaub mir!

fff