The Gui based configuration tool for backups on SBS 2011 is totally useless. Here are some command line based tools:
wbadmin enable backup
[-addtarget:<BackupTargetDisk>]
[-removetarget:<BackupTargetDisk>]
[-schedule:<TimeToRunBackup>]
[-include:<VolumesToInclude>]
[-allCritical]
[-quiet]
Syntax for Windows Server 2008 R2:
wbadmin enable backup
[-addtarget:<BackupTarget>]
[-removetarget:<BackupTarget>]
[-schedule:<TimeToRunBackup>]
[-include:<VolumesToInclude>]
[-nonRecurseInclude:<ItemsToInclude>]
[-exclude:<ItemsToExclude>]
[-nonRecurseExclude:<ItemsToExclude>][-systemState]
[-allCritical]
[-vssFull | -vssCopy]
[-user:<UserName>]
[-password:<Password>]
[-quiet]
Example for adding a series of volumes: wbadmin enable backup -include:c:\,d:\,h:\
This adds volumes to the backup. Note the backslash after each drive letter.
More here: http://technet.microsoft.com/en-us/library/cc742130%28v=ws.10%29.aspx