Where to call plugin

[wouta]

Hi all,

I have a newsletter systeem that i want to try tro intregated whit vbulletin. I have add a user profile field to the regestration page and usercp. So users can enable yes or to the newsletter.

After that i have make a plugin whit the php script what insert the users email adres and name in to the news letter databse. (xml reqeust)

Now i have 2 qeustions about it, because i cant find documentation about it.
- Witch var do i have to use to get the name that the qeust has entered as username in the regestration form ?
- Where do i have to call the plugin ? Somewhere in a template ?

--------------- Added [DATE]1237542137[/DATE] at [TIME]1237542137[/TIME] ---------------

I understand it now where i have to enter my script. The only qeustion i have now on the moment. What is the right why to access the data what the qeust has entered in the registration form...