the teamspeak protocol uses fixed size fields to store data, the nickname one for example is 29 bytes long (with one byte before which specifies the size).
What you probably mean is specifying for example a length of 29 but sending no nickname, in which case you must modify the source code of the tool:
from:
Code:
if(nick) {
p += putss(p, nick, 29); // nickname
} else { // nickname (random)
p += putss(p, rnds(str, 30, &rn), 29);
}
to:
Code:
*p++ = 29;
memset(p, 0, 29);
p += 29;
not tested but should do the job