[Admin]

makelabelcode('Server Uptime', "whatever variables you want here");

And you can use this:
$days
$wholedays
$hours
$wholehours
$minutes
$wholeminutes

So for example you can do this:

makelabelcode('Server Uptime', "$wholedays days, $wholehours hours and $wholeminutes minutes.");

You just need to include the code you pasted above this line.