The Imbedded Interface Point (IIP) for VLF-WIN is the component specified in the Framework's Details tab.
To get there menu (Framework) --> (Properties...) --> Framework Details tab.
The option is User Imbedded Interface Point: (Id). The shipped value for this is component UF_SYSTM.
To do your own IIP Windows checking, all you have to do is create your own version of UF_SYSTM with a different name, and then edit it and modify the relevant method routine to do what you want it to do, compile it, and then change the option from UF_SYSTM to the name of your version.