Rez object and attach from HUD?

I am trying to create a HUD that when clicked on, will create an "extension" to itself that can display extra informtaion. I assume I need to rez the extension and then attach it to the avatar, but I'm not sure how the code would go to do this. Does anyone have any code snippets they would mind sharing or any suggestions as to how this would be done?

Thanks you in advance for any help you may be able to give.

Why rez it?

Have the extra off screen, and move the screen into view when required. Much neater than rezzing. No spamming blue boxes, etc.

llSetPos and llGetLocalPos are your friends for this.

Eloise has the right of it..

..otherwise, you cannot create links to attachments, and you cannot attach something else from inventory to an avatar via script. You can make a scripted object that is rezzed attach itself to an avatar, but if it is already rezzed, you would be better off using Eloise's suggestion.