The fixed blade I'd grab would be my EDC made by Nathan Carothers, which I do often carry in my work bag anyways but hard to put on the belt all the time.
Untitled by GaryWGraley, on Flickr
G2
What does that little fixed blade have? About a 3 inch blade? Make yourself a little pocket sheath and carry it in your pocket. Then you don't need to put it on your belt. I recommend the left front pocket. Keeps it out of the way if you are right handed, but easy enough to get when you need it.
O.B.