Preselect a tab in the 'New SharePoint Site' page

I tried to find the answer to this one for too long. It may be obvious to most intelligent people but this one’s for the rest of us.

In our SharePoint site we make an individual site for each project and these are all kept under one Project Management uber-site. This means that we’re often creating new project sites using a custom template I’ve developed.

I wanted to provide a simple link which would shortcut to the create a site page and pre-select the appropriate custom template. Thanks to some advice here I’ve got halfway there and can now make my link show the appropriate tab. The trick is to simply add ?DisplayCategory=TabName to the URL.

In my case because I’m using a custom template I want the custom tab selected, so:

https://sharepoint.oursite.ac.uk/IS/Projects/_layouts/newsbweb.aspx

becomes

https://sharepoint.oursite.ac.uk/IS/Projects/_layouts/newsbweb.aspx?DisplayCategory=Custom

Any help with pre-selecting the actual template would be appreciated.