You can search for Star Trek or Federation fonts online. Lots of places have a lot of different ones. Depending on which ship/era you are modelling, the fonts are different. I used "Federation Starfleet Hull 23rd" font for a custom registration of a TOS Enterprise kit (since the available registration decal sheet didn't have all the letters I needed).
One site that has a lot of different ST fonts is http://www.talshiar.org/Fonts/. It doesn't have the specific font I used, but it may have the one you are looking for.
Paul