Can I change the business object instance caption that appears in the area above my command handlers?

Yes - use this operation:

#Com_Owner.avHandlerCaption := 'My alternate caption'

You can append a suffix to the main window title by doing this:

#Com_Owner.avWindowSuffix := 'My Window Suffix'

In VLF-WIN applications you can also append to the title bar captions by doing this:

#Com_Owner.avTitleBarSuffix := 'My Title Bar Suffix'

VLF-ONE

VLF-WIN