My team has a template (XDP) that we\'ve created with the Adobe LiveCycle designer.
The situation:
We are replacing an old Acrobat form (XFDF format
Sounds like you're looking for client-side rendering - something that I've never really been able to use in a workable fashion. And given that you're working in .Net it'll probably make things impossible..
In my opinion your best bet will definitely be to use the render service that comes with Forms ES. Probably doesn't help much, but hey :)