WebCM- How do you change the content type of auto-generated default.aspx pages?

I'm using MOSS 2007 for web content management, creating "Publishing Site with Workflow" subsites. When a subsite is created, default.aspx is auto-generated in the Pages library and set as a "Welcome Page" content type.

Is there a way to change the content type of this generated page to a different type and save the change as a site template in a way similar to the collaboration site