if you want to do it in code, its also relatively straightforwards...
Sub AddAModule()
Dim md As Object
Dim wb As Workbook
Set wb = Workbooks.Add
' you can (a) programatically add a module
Set md = wb.VBProject.VBComponents.Add(1)
and also (b) import a text file as a module
Set md = wb.VBProject.VBComponents.Import("{full address here}")
With md
'blah
End With
End Sub