Apply character style to whole word which contains a letter

For exporting the matched words to a file you can use the following script

var doc = app.documents[0]
app.findGrepPreferences.findWhat = "[\\l\\u]*[nN]+[\\l\\u]*"
var f = doc.findGrep()
app.findGrepPreferences.findWhat = NothingEnum.NOTHING
var s = ""
for(var i = 0; i < f.length; i++){
    s += f[i].contents + "\n"
}
if(s != ""){
    var f = new File("~/Desktop/out.txt")
    f.open("w")
    f.write(s)
    f.close()
}

I could not make your regex work so I used @pixxxelschubser's regex. You can change the regex to what you want in the code in line no. 2, just make sure you escape \. The script will create a file names out.txt on the desktop

-Manan