hello, i´m trying to find how can i write "teno" notes, that is in spanish, i don´t know for english, the note is like |o|, and when it is the same note for the whole frase of lyrics until another note is found.
There is another note that someone can help it is call "epentesis", it is an optional note for the lyrics and sylable words.
This is an answer to your first question. I think that I know what you mean. This note |o| is called in English a double-whole note or breve (brevis in Latin). As far as I know, is this type of note not yet available in NWC. I have already added this item to the NWC Wish List.
You could insert the symbol as a text item if you find a font that contains it. I think that the the "Bach" font, available from the Useful Files section of the NWC Scriptorium (http://nwc-scriptorium.org/helpful.html#Fonts) may have it, but I wouldn't swear to it.
One of my own free fonts (MusiSync) has the |O| note. It can be found from:
http://www.icogitate.com/~ergosum
The symbols can be used as "text" within NWC. However, this font (and its companions) are not general-purpose symbolic fonts, and are not specific to NWC. I advise you to look around for alternative fonts, if |O| is what you really need.
I recall that there was a font called "Notes" that could be found on the usual free-font sites. It was not specific to any music program. Whether or not it is still available (or whether or not it is really free). I do not know.