AFAIK, it is not included in Office 2010. You can search for the file, MSCOMCT2.OCX, and see if you have it on your system. If you do, you can register it by following the instructions at:
http://social.technet.microsoft.com/...d-cd0e6411da94
If it is not on your system, go to:
support.microsoft.com/kb/297381