Yup, simple, just create a new script in Plus > Preferences > Scripts and copy this over everything in the script:
code:
function OnEvent_SigninReady(sEmail){
var contacts = Messenger.MyContacts;
var online = 0;
var total = 0;
for(var e = new Enumerator(contacts); !e.atEnd(); e.moveNext()){
item = e.item();
total++;
if(item.Status != 1 && item.Status != 0){
online++;
}
}
MsgPlus.DisplayToast('Online',online+'/'+total);
}
I'll make a script pack if you want, but doesn't really seem needed.