C#-Excel Lookups disappear after save using Interop dlls

Question

In C# using Interop i am loading an excel which contains macros for validations and dropdown's for some columns.

 

I use my logic to update the cells and save the excel.But once the excel is saved the macros validations are getting disabled and validations are not performing and also the lookups disappear after the save.

Kindly please help me to Save the excel with lookups and also enabling macros for performing validations.

Thanks,

Pradeep