Hey!
I'm not too sure what you mean by smallcaps... do you mean text Lɪᴋᴇ ᴛʜɪs?
If you want to just have small capital letters, you can use the tag <s=0.5> to have certain text be smaller than others. (The <size=5> will set the text's exact size, not relative size like <s=0.5> does) Besides that, you'd have to make your own pre-parsing script to generate these special smallcaps characters from the normal ASCII data. This method can be done with a standard text mesh too, so it actually falls outside of my jurisdiction, but if you need help getting started, check out the other preparsing examples included with STM to see how to do custom text modifiers!