There is a sample project for custom form layout that we ship with the Quest Web Part installer.
Please check your installation folder
..\Program Files\Quest Software\Quest Web Parts\Sample Code\ple CustomActionsAdCustmLayoutFolder
and open the solution using Visual Studio and go to the file pleLayoutManager.cs file. You'll find there all the info you need to build your own custom layout.
Please let me know if you have any questions.