Open your desired project file in FCP (a file that has already been digitized and has a project title).
In the Browser window, under the tab for your project, right click and select "New Sequence." This will open the Timeline window for your new sequence. Drag all of the movie clips from the Browser window to the Timeline window in the order which you want them to appear on video track 1 (V1).
If there is only one video track, be sure to add another by right clicking on the left panel of video tracks and select Add Track. Put the source cursor on an empty video track (this is the track which will contain the subtitles).
Cue the time line so that it corresponds to the point in the movie where you want the subtitles to begin. Press the "i" key (for input) to begin the segment. Then cue the time line so that it corresponds to the point in the movie where you want the subtitles to end. Press the "o" key (for output) to end the segment.
You now should have a highlighted segment of your video clip in the Timeline window. Go to the Viewer window and right-click on the subtitle button in the lower right-hand corner (looks like the letter A). Go to the Text menu and select Lower 3rd. This sets the space for the subtitles in the lower 3rd portion of the video.
Go to the Canvas window and click the red Overwrite button in the lower left-hand corner. This will create a new clip for the subtitles in your new track. If you do not see a clip called "Lower 3rd" in the Timeline window, please repeat from Step 1.
Double click the "Lower 3rd" clip in the Timeline window. This will open the clip in the Viewer window.
In the Viewer window, open the "Controls" tab. This will open the control panel for inputting subtitles.
Next to Text 1, enter the subtitles for this segment of the movie. You can also change the various text parameters here (font, style, size etc.). The text entered into this Text 1 box will be rendered only on one line so, when you are done, it is important to click the Video tab in order to check that the subtitle appears correctly and within the frame of the movie (the turquoise boxes). The Text 2 box can be manipulated in the same way as the Text 1 box. This could be used for a continuation of the Text 1 box's contents in the same language or as a translation.
If you wish to make another subtitle for another segment of the movie, please repeat from Step 1 of Making Subtitle Clips in FCP.
Export the subtitle track you want to use as an XML (turn off all other tracks so it's just subtitles in the XML).
Open TitleExchange Pro. Go into "Preferences" and click on "Conversion". For Input File Format click "XML". For Export File Format click "STL". If you want the text to export as a particular font that's different from the FCP sequence, select STL/QTtext Settings and select your desired font, size, etc… Close the window.
In the main window click "Import Subtitle File" and select your XML.
Select your subtitle track. If you exported just the subtitle track, than it should be the only one available for selection. The file should export to a .txt file automatically. If you need an .rtf you can open the .txt in Text Edit and then resave as an .rtf.