preg_split help

[Hellboyz]

Hello, I've read a couple tutorials on regular expressions but I just can't wrap my head around them. I am trying to split a string into an array using preg_split but so far I can't create a expression that will work.

The type of data I would be working is like:

[Something][123456789][Hello]

and I would like to split that into three separate places on an array like:

0 => Something
1 => 123456789
2 => Hello

Anyone know how to do this?