Near the start of the bloggar\CMS\CMS.ini file, bump up the count by one.

Like this:

  [CMS]
  Count=11

Then add following to the end of the CMS.ini file. Change 'yourserver.com'
to the address of your Roller server. If you want the icon to work then drop 
rollerbadge.jpg in the same directory as CMS.ini.

  [CMS-11]
  Name=Roller
  URL=http://www.rollerweblogger.org
  Icon=rollerbadge.jpg
  Service=0
  Host=yourserver.com
  Page=/roller/xmlrpc
  Port=80
  Https=0
  MultiCateg=3
  GetCategMethod=3
  PostMethod=3
  GetPostsMethod=3
  TemplateMethod=1
  
If you are a FreeRoller user, then here are your settings:

  [CMS-11]
  Name=FreeRoller
  URL=http://www.rollerweblogger.org
  Icon=rollerbadge.jpg
  Service=0
  Host=freeroller.net
  Page=/xmlrpc
  Port=80
  Https=0
  MultiCateg=3
  GetCategMethod=3
  PostMethod=3
  GetPostsMethod=3
  TemplateMethod=1