If you just want to read the code in each modules you just have to go through the 'Workbook.VbaProject.Modules' collection like this:
var fi = new FileInfo(@"C:\temp\Book1.xlsm");
using (var pck = new ExcelPackage(fi))
{
var modules = pck.Workbook.VbaProject.Modules;
foreach (var module in modules)
{
Console.WriteLine($"Module Name: {module.Name}{Environment.NewLine}Code:");
Console.Write(module.Code);
Console.WriteLine("---------");
}
Which will give you this in the output (I just created an excel xlsm with two modules):
Module Name: ThisWorkbook
Code:
---------
Module Name: Sheet1
Code:
---------
Module Name: Module1
Code:
Public Sub proc1()
Dim wb As Workbook
Set wb = ActiveWorkbook
Dim ws As Worksheet
Set ws = wb.ActiveSheet
ws.Cells(1, 1).Value = "proc1"
End Sub
---------
Module Name: Module2
Code:
Public Sub proc2()
Dim wb As Workbook
Set wb = ActiveWorkbook
Dim ws As Worksheet
Set ws = wb.ActiveSheet
ws.Cells(2, 1).Value = "proc2"
End Sub
---------