If the receptionist does not allow you to meet the officer, you may directly call the officer in his/her mobile/landline and talk to to him/her.
Caution: Explosive. Handle with care.
The situation here is one where the receptionist is caught between a rock and a hard place. If he/she allows you inside, they have to face the wrath of the boss; if they do not allow you, they'll face your anger. The trick here starts with the body language and confidence. Approach the receptionist with an air of authority that conveys that you are used to these situations. If you hesitate or stammer and do not speak out, you'll never have a chance. Then be clear and firm that why you are here and see the response. Then tell in crisp concise phrases that she has an option of call up the boss or you walk through the door, I have to be inside either way and the choice is yours but if I were you, I would pick up the phone at convey this to the boss.
If we have approached her at a time generally not allowed for visitors and we have some real urgent unavoidable reason, then we have to be polite, and persevere, so that she takes us serious and becomes convinced that we are genuine. After all, receptionist also is human and there can be problems if it later turns out that something happened due to her negligence or her action in denying the permission. So receptionist may have a rethinking and may relent .
I am sure if the matter is so urgent and unavoidable and there is no other alternative, then we also will take all our efforts to gain entry. We may have to plead,beg , flatter, throw names , utter technical and legal words and sometimes even threaten. (We may apologise to receptionist later after our purpose is over.)
Many of my generation people know the Technic of perseverance practised especially when we had to travel by train without getting reserved berths. We would be following the TTE like a shadow, begging and pleading until he gives us a berth. We may be ready to any compromise because we are in need.
The same technique is to be used with the receptionist in the present stuation also.