You're referring to ADD TEXT?
If they're TrueType (ttf) fonts, they should appear in Videopad. Installed Century Gothic here, and it became available. Can't speak for NON ttf fonts??
After typing your text click on the large "T" or "A" beneath the clip preview window.
Then click the small arrow to the right of the "font" field, to reveal the drop-down box that displays the available fonts..