I don't know of a built in slack command that will do this. However, you can make your own custom slack commands. Here is a link to some documentation.
https://my.slack.com/services/new/slash-commands
Also, for a more complete answer. Here is a list of the built in slack commands.
https://get.slack.help/hc/en-us/articles/201259356-Using-slash-commands
Hope that helps!