There is probably an undground parking area/utiltiy cupboard that you can use. Have a poke around the basement . If you ask, the answer will probably be "No we dont have anywhere", so look around first then prepare your "case".
Where do workers park their cars normaly.

Once you do find a place, pref under CCTV observation, leave a heavy duty chain and padlock at work, and carry a smaller lighter lock.

If there really is nothing to bolt your bike to, then get your building manager to bolt a wall-mounted security attathment to a suitable wall. If all this fails, just park your bike in the middle of your normal parking area.