Welcome to SciTE-st. Before you ask your question, please try and be sure it is not addressed in either:

1) the SciTE documentation (http://scintilla.sf.net/SciTEDoc.html)

2) the Manual (http://caladbolg.net/luadoc/scite-st/manual.html)

3) the Lexer documentation (http://scite-tools.googlecode.com/svn/branches/scite-st/lexers/lexers_doc.txt).

You may be able to get a quicker answer that way. Thanks :)