This isn't possible.
You can't use .ins files with VSTi's.
The only way I've ever got this to work was to host the VSTi in a separate program (e.g. Cantable) and set up a virtual MIDI port between the two. But the downsides to this with audio routing overwhelmingly outweigh any benefits you get from using an .ins file.
It's best just to use the VSTi's GUI to select the patch.