Centering Subcategories?

I have my subcategories as a drop down vertical template which is great but my

problem is I have alot fo categories and some categories have a large amount of subcategories.

So when someone points on a category and it shows the subs from that category down.

sometimes the main category could be towards bottom of list so when they point on it they see the subs from that position and down. so that if the category is say 10th on the list then the subs would be from that position and lower.

This makes it awkward for customers as they have to look way down on page to see all

the subcategories.

Would like to have the subcategories vertical but to be centered on page somewhat. Instead of starting at the categories position and going down.

I believe i found the template to be changed at

public_html/design/themes/responsive/templates/blocks/categories/categories_dropdown_vertical.tpl

But dont know hw to change it. If anyone can help would greatly appreciate it.

categories_dropdown_vertical.tpl