It is in the receiving code from the link I gave you.
// the data to be split "x,y,z,s" => "111,222,333,444"
x=atoi(strtok(c,",")); // strtok will look at the split point ",", and will return everything before it, so x = 111
y=atoi(strtok(NULL,",")); // this will continue off from where the first line ended, and will look again for "," and now y = 222
z=atoi(strtok(NULL,",")); // same here
s=atoi(strtok(NULL," ")); // this is looking for a space " " again s = 444
//The atoi() function will convert an array of chars {'1','1','1'} into an actual int 111. Here I just combined both functions into one.
added: just read James C4S's post