Order Links - Selecting Product Options

[CP-Chris]

Hi Everyone,
I've been played about for the last few hours to find the variable which will allow you to change a config option when using a direct link such as: http://demo.whmcs.com/cart.php?a=add&pid=1

I have tried: http://demo.whmcs.com/cart.php?a=add&pid=1&configoption[X]=XX
also have tried:
http://demo.whmcs.com/cart.php?a=add&pid=1&fieldname=description

But neither works. Is this even possible? Any thoughts or ideas greatly appreciated. Googling and forum search hasn't found anything other than: http://www.whmcs.com/members/communityaddons.php?action=viewmod&id=21 which I dont think is quite what I need.

Kind regards.
-Chris

[CP-Chris]

Right, sods law I post this and then find the answer, this functionality was added into version 4.1.1+ and uses the method: configoption[X]=XX

Hope this helps someone else who may get stuck :)