Alignment of subtitles on a slideshow

When i add subtitles for a slideshow it is posible to write a % to especify the alignment. 0% on the top and 100% the bottom of the screen.
It is posible to align the subtitles to left or right of the screen?. I need to show the photos as big as i can and don't want that subtitles overlap the photos. I'm trying to do that without resizing the photos and in photos with great height it may be a solution to align left or right.

Thank you very much.

You can use any of the settings in the Character tab on subtitles in Slideshows, including Align Left, Right, etc.