Custom animations

Hi there! I was curious if there is a way to set up custom animations
so that a div will expand from a specified corner to another specified
corner?
Ex. If I have a div with a background color of #000 that is 200px by
200px and when I hover over it it expands to 500px by 500px from top
left to bottom right, by default. I want it to expand from top right
to bottom left or bottom right to top left, etc.
This is how I have it set up
but it only goes from top left to bottom
right
$
'div.item'
.hover
function
{
$
this
.animate
height: 500px,
width: 500px

;
}
;