Perl Script; adding sub-categories Password change option

Im currently learning about script uploading using perl and am having a couple of problems with an auction script.

Basically I dont know how to add subcategories to subcategories, i.e:

Automotive - Cars - Aston Martin.

For some reason the script only comes as 2 categories, the main page category and subcategory, i.e:

Automotive - Cars.

Ive been told I would need to add another background template to enable a third category, which again i dont know how to do.

The other thing is passwords, when you register with the site you automatically get given a password, you cant make your own one up and you cant change the password thats been sent to you, i need the script edited to allow the above.

I need someone asap to do these bits of editing for me then show me exactly what changes have been made so i know for next time.

The jobs shouldnt take long really as ive done the majority of the editing already, but obviously I will pay the person a fee foe their troubles which we can discuss further through email.

I need this done urgently as Ive had these problems for a while now and need them sorted or the site cannot be pubished.

I have attached the un-edited version of the script.

Please contact for more details asap! thankyou.