Access synced Exchange calendar from desktop browser
If you have Outlook 2007, you can use the built-in Publish My Calendar feature to publish it to Microsoft servers, which will make the ICS feed available to add as a calendar in Google Calendar.

In Outlook 2007, go to the Calendar section and click the "Publish My Calendar..." link. Fill out that dialog and it will start syncing.

If necessary, feel free to adjust which calendars are shown in your Android device via the Calendar app's Option menu item "Calendars".