You can add your custom link to Communicator help menu. This allows you to push customized help content to your OCS users. Administrators can configure this using group policy setting.
Steps to add custom help menu items are as follows:
1. Open registry editor and go to the following registry entry
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Communicator
2. Add the following keys to above mentioned entry
HelpMenuText (Type: REG_SZ) , value specifies menu caption
HelpMenuURL (Type: REG_SZ), value should point to a valid network address
Now close the registry editor and restart Microsoft Office Communicator 2007, new help menu option should be available.