Choose View|Toolbars. Make sure that the Regions/Playlist Toolbar is selected. If you have everything hooked up properly, the Time Code will go streaming by in this Toolbar when you turn on the external device. Under the Options menu make sure that MIDI Input Sync/Trigger is selected. Under Options|Preferences choose the MIDI/Sync tab and make sure that your settings are on the proper input and output device that's carrying the MTC.
If you need to set up playback offset, you will find the control on this page. Create a region out of the part of the file (or the entire file) that you want the external device's MTC to trigger. Then Press Alt+1 and Alt+2 to open the Regions List and Playlist, respectively. Drag your region from the Regions List into the Playlist. Double-click on the region in the Playlist. Open the drop-down list under Trigger and scroll down to choose SMPTE: Play at Time. Then set your SMPTE Time.