nikon:STILL, I think there must be a better way, don't you think?
There is really no need to do it that way. Type the title, then the tab key, then the composer. No spaces needed. Go to the tab controls, set a right-sided tab stop at the right edge of your text box, and use a period for the fill character. Just for the record, there is space in the fill character field for two keystrokes, so if you want tight leader dots, use two periods, and for looser, use a dot and a space.
Tab stops are a paragraph attribute, so you can make a paragraph style and apply it to each <title-tab-composer> item, and not have to muck around with drawing lines manually.