Using pathogen with a custom compiled vim

Pathogen is great for managing your plugins but it needs to know if you changed the default ~/.vim to another folder with the path VIMRUNTIME, so you have to export it INSIDE vim, yeah i don't know why.
So if you want pathogen to succesfully rebuild the help tags of your plugins when you do

:call pathogen#helptags()

You have to add this to your .vimrc

:let $VIMRUNTIME='/path/to/the/root/of/your/vim/installation/'

For regular users VIMRUNTIME leads to .vim in my case i compiled vim to be installed in ~/apps/vim73 so i had to add:

:let $VIMRUNTIME='~/apps/vim73'

To my .vimrc hope it helps somebody with the same problem.