strKeep (Delete excluded chars)
info("str strKeep(str _text1, str _text2)");
info("Deletes all of the characters in a text string that are not included in another text string.");
info("_text1 - The first text string.");
info("_text2 - The characters to keep in the first text string.");
info("strKeep(\"ABBCDDEFGHB\",\"BCD\") " + strKeep("ABBCDDEFGHB","BCD"));