ABBYY Fine Reader Plugin to GUI

Hi,

I am new to COM/.NET programming.

I have to write a plugin for Abbyy fine reader that should appear as a tab to their standard toolbar.

Abbyy provides SDK for extension to their engine. I am using C# and visual express 2010 for this as I think this requires COM programming.

Can you please guide in terms of how to proceed and in terms of also feasibilty of this.

Is it always possible to add one of our plugins to front end of some other application by working out interfaces in vendor's DLLs ?

thanks