Rewrite Rule Help


Right I've decided that I'm going to be a xenforo convert and move over from vbulletin, which means I need to start planning how I'm going to do this as smoothly as possible.

I'm going to have wordpress in the root of my domain and xenforo in a folder called forum. I think I'm going to do this in two stages firstly get xenforo up and running and once that's setted in, I will set up wordpress after a month or so. I'm currently using the vbulletin suite and I've got it installed in the root of the domain.

Can anyone help me with what rewrites I'd need to put in the .htaccess file for the following 2 situations.

Firstly I want to temporally redirect all urls that can be used to access my site to a holding page called offline.html in the root of the domain but I need to be able to still access the site as normal from my IP address.

Secondly once I've got xenforo setup I want to redirect any of the urls from the root of the domain to the xenforo home page again I need to still access the site normally from my ip.

Thanks in advance to anyone that can tell me what i need to put in my .htaccess file.