I was wondering if it's possible to initiate Excel macros (Excel file is located on a network drive) from SharePoint? Are there any add-in features within SharePoint that can communicate with macros?
In a word, no.
SharePoint Server can host Excel workbooks in SharePoint pages using Excel Services, but these do not support Macros (for various reasons, the main one is to prevent malicious code from being executed).
Just to clarify this is not referring to running Macro's in Excel Workbooks stored in SharePoint - that is definitely do-able in SharePoint 2013!