Does my steering rack (1998 Corsa) need replacing?

My car (1998 Corsa 1.6 16V sport) has been subject to an attempted theft and the outer cowl of the steering column is damaged. The steering lock and ignition both still work and the car seems to steer OK. Is there any way to tell if the steering column itself is actually damaged and needs replacing (£500+ job) vs just "cosmetic damage" (less than £100 job)? I want the car to be safe but I don't want to spend £400 un-necessarily.

Annie J
October 2008