Creating an alias to post in a group

Hello, my job has a collaboration group called 'OUT' for employees to join. We have several leaders in the group. For example: I am the manager of communications, so I am the one always posting updates to the group. I am trying to see if I can make my posts show that they are posted from "OUT Communications" or something similar of the type. And for other managers of the team to be able to post as "Group leader" or "Events Committee" etc. But I also want to be able to post or comment on things using my real username.