Delphi Applications - Virtual String Trees (VSTs)

I'm testing Delphi applications that use Virtual String Trees (VSTs) a lot and I am struggling to get TestComplete to recognise these objects. As of yet I have not been able to work out which Project Property > Object Mapping I need to add this class to in order to identify properties within the VST.

 

When I use the object spy and select an VST object it returns the error "Error: An exception occurred: 0x0EEDFADE; class: EComponentError; description: 'TVirtualStringTree has not been registered as a COM class'" on the ComObject property. I am using debug builds of the Delphi applications.

 

Has anyone else got experience using VSTs within Delphi applications? If so, how did you do it? They typically store a lot of information therefore not being able to read the properties of them makes it difficult to test the application properly.