If you have the symbolic toolbox, you can use sym() to parse the expressions, after which you could use matlabFunction to generate a function handle that can evaluate the expressions on inputs.
You will want to use the matlabFunction 'vars' option to control the order of the inputs; you might want to set it up to take the values as a vector, something like
matlabFunction(symbolic_expression, 'vars', {[a, b, c]}
If you are going to be repeating the calculations many times, you might want to go as far as to tell matlabFunction to write to a file: when it writes to a file then it defaults to optimizing the code, a process that takes a bit of time but might be worth it for repeated execution.
