Hysys Reaction Extension - Get Activity Values

[aria]

I am developing a Hysys reaction extension for Methyl tert-butyl ether.
The extension is developed in Visual Basic. The reaction rate is based on
component activity! so, I need to get the values for activity inside
VB code! Does anybody can kindly advise me how to get these values
in VB.

Thank you

[SIM2]

Dear Aria
regarding developing Hysys extension ,Do you have any idea about how to give the new extension an icon or the shape (Picture or the background pictures like that used on the built in unit operations .