Have not done similar things but might be able to inspire you a bit...
All events is found at the bottom of this page: 2014 SolidWorks API Help - SolidWorks.Interop.sldworks Namespace
I would start using 2014 SolidWorks API Help - DPartDocEvents_RegenNotifyEventHandler Delegate (SolidWorks.Interop.sldworks) and 2014 SolidWorks API Help - DPartDocEvents_RegenPostNotify2EventHandler Delegate (SolidWorks.Interop.sldworks) .
What I would watch is the 2014 SolidWorks API Help - GetUpdateStamp Method (IFeature) for the specific feature. Assuming you know what the feature name is or that you only have one of that kind... somehow the feature must be known.
To get the assembly references see this post:VBA code to get list of references (File->Find References)