Dll's for Area Calculations OpenRoads Designer, Visual Studio, C#

I have OpenRoads Designer CE 2021 Release 2 and Visual Studio 2022.

Using C# I wish to access the Measure area tool under Analyze/Measure/

How can I access this tool and add/remove  some UI/functionality. Can you please point me to any documentation on what  Dll is being used and how to use it? Appreciate!