I have been doing a lot of data migration and disaster recovery synchronization lately and had a need to run DOS commands quite frequently.  It was a pain to switch from SSMS to the command window or prompt and then run the DOS command or even more interesting the batch files I just exported.  So I found a way to run it from within SSMS.  

Type in your command and make sure to prefix it with two exclamation points !!  Then click the SQLCMD button on the tool bar and then hit Execute (F5) and voila, it runs!