Thread Subject: evaluating expressions obtained from UI. eval alternative

I often write user interfaces that require user to input
analytical functions into edit boxes.
But I haven't found a MATLAB function specifically designed
to handle the scenario.

I tried different ways to accomplish this:
1. I tried the subs function from symbolic math toolbox -
it's robust, but is veeeery slow ((

2. Now I use eval. But it requires users to input
expressions using non-matrix operators like .+ .* etc.
Moreover, eval is not robust at all: users are able to
execute almost any MATLAB command inside my UI. Yet, eval is
not as fast as I want.

Any suggestions?
TIA