Multisite Domain issues

Hi Everyone,

First post so be gentle!

I will try and keep this as clear and concise as possible.

I have a path based multisite network

Each site/user on the network is created from a third party system via an api call

All sites are accessible via http://www.mydomain.com/username (the actual wp domain) or http://www.theirdomain.com/blog (achieved with some redirect rules on said third party system)

When the user hits the blog from http://www.theirdomain.com/blog the blog is served up as expected. However the links accross the site are in the format http://www.mydomain.com/username/whatever.

Obviously when a link is then clicked the user is bounced back to http://www.mydomain.com/username/whatver.

I have explored converting all of the urls to relative urls but this is messy and doesn’t work accross all plugins/themes etc. and is something I want to avoid.

I don’t want to go down the route of using a Domain Mapping plugin or similar as this will add in a layer of complexity for my users that I want to avoid, messing about with DNS records etc. and I really want everything to run through http://www.theirdomain.com/blog for SEO purposes as opposed to blog.theirdomain.com or anything like that.

What I am trying to achieve is keeping the site mapped to mydomain.com/username but actually thinking it is on theirdomain.com/blog whilst keeping all the links and stuff the same.

I have managed to get it working in a single site setup by simply changing the site url and home url, so it thinks it’s at someotherdomain.com and creates the links accordingly but it’s actually all being served up by myactualdomain.com

I hope that makes some sense, this is my first multisite install and I’ve been battling with this for a few days now so I’m a bit boggled by it all.

Many thanks in advance

Ben