Ok first off, the cookies name has to be a valid value to be used, so it must start with a valid character, it cannot start with a number as you have done, the value on the other hand can be just about anything you want it to be.
Lets re-code this.
$string = "cookiename";
$test = 76;
setcookie($string, $test);
This would create a cookie called cookiename that will expire whenever the user closes their current browser window.
You can ad on an expiry time, a path, and a domain and some security stuff, but out of those the only one you'll probably ever need to use is the expiry cause the others are already taken care of as long as the cookie's for use on the same server that it's created on.
As for using it on another page, well that depends on you servers config for php, but most likely it's all default stuff so the cookie will be recreated on every page on the site by php into a variable of the same name of the cookie, so our cookie name being "cookiename" the variable would be $cookiename. So if you tossed the following code onto another page on the site it would display the contents of that cookie, which in this case would equal 76.
echo $cookiename;
And for your other question, cookies are passed behind the scenes between the server and your browser (ie, netscape, etc.), if you want to pass the value for it through the command line instead as part of the URL then all you have to do is somthing like this.
http://www.myserver.com/pagename.php?cookiename=76
And this would pass the variable $cookiename onto the next page, though it's may or my not override the cookie value, it all depends on your server's php.ini file which has a setting that governs which methoods take priority. In which case you'd have to use the HTTP_COOKIE_VARS[] and HTTP_GET_VARS[] arrays and determine which one you want to use on your own.
Anwyays I hope this explained it without getting too deep into the technical stuff.
