Usage of a portable app within an user account without admin rights

Suppose the portable app named "Appname" stores its settings in a registry key HKLM\Software\AppName. Furthermore I will run this app within an user account without admin rights. Let me now distinguish the following 2 cases:

1. Case 1: App requires admin rights

I think, that in this case the portable app will quit. The only possibility is, that I insert the following code in the file AppNamePortable.ini:

[Launch]
RunAsAdmin=force

This code causes the user to be prompted to run the program as an administrator (or a UAC prompt on Windows Vista or Windows 7 when UAC is turned on).

2. Case 2: App requests (but not requires) admin rights

   In this case the app will run and probably write nothing in the registry. But I can again insert the following code in the file AppNamePortable.ini:

   [Launch]
   RunAsAdmin=try
   

   Now the user will be warned that some features of the portable application will not work. The users can now decide, if he wish to run the app with admin rights, so that he can use all features of the app.