Hi guys. Autodesk took down all 'user' authored articles in the 'knowledge.autodesk.com' domain back around March 8-10 this year. Ahead of that date, we were instructed to copy our content elsewhere or it would be lost. I think I had somewhere in the range of 34 to 38 articles in there at the time, so for the sake of expediency I just choose to copy the contents of the better ones to new local Microsoft Word documents, then made PDF's out of them. That way I can just attach the PDF file in a post once in a while, instead of a link. Those articles were pretty limited by character count though, and did not allow most types of attachments, so the content had to be brief.
Creating a good looking and fully functional Windows form from scratch within an iLogic rule is definitely not the easiest way to do things, but once the initial work is done, it can be pretty rewarding, and without much 'overhead' at all. Then if you wanted to take it another step higher, the Class you create for the Form can be placed into an external rule, with the option set to 'Straight VB Code', and then referenced from another rule using 'AddVbFile' (followed by the name of that external rule) within the 'Header' of the rule, so that you can call it to show from another rule. But as Jelte mentioned, if you are good with vb.net, have Visual Studio installed, and can create your own DLL's, it could certainly be done much easier that way.
Attached are two PDF's that were created from two of my old articles which both included creating & using Windows Forms within their iLogic rules. I have not had the chance to update them since that point, so they may be a little 'rough around the edges'. The one working with iProperties was created before the whole 'ModelStates' complication was an issue, so it likely needs a version 2.0 now. There were others too, but they were more customized for my work use, so I chose not post them online. I hope these may help out a little. I have not attempted to coordinate the design/layout of a Form to fit specific locations of a custom background image like that before though.
Wesley Crihfield

(Not an Autodesk Employee)