All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
No doubt that praying in congregation in the mosque is better rewarded and more appropriate than praying in congregation elsewhere. But if the person has an excuse that prevents him from going to the mosque and as a result, he establishes congregation in his home or his place of work, then that is acceptable. Having said so, we believe that you should try your best to convince your superiors to permit you to go to the mosque. But if they refuse, then there is no objection to your praying in your office and in congregation if possible [i.e. with some other employees].
Allah knows best.