I have the following two Sub defined in my Word Addin (.dotm) which I have put in StartUp directory
Public Sub SayHi1()
MsgBox "Hi......."
End Sub
Public Sub SayHi2(ByVal n As String)
MsgBox "Hi " & n
End Sub
Then from a new document I am able to call 1st Sub without argument as below:
Sub AppRun_AddIn_NoArg()
Application.Run "MyProject.Module1.SayHi1"
End Sub
But when I try to run the 2nd Sub with argument I get error saying "Object doesn't support this property or method"
Sub AppRun_AddIn_WithArg()
Application.Run "MyProject.Module1.SayHi2", "Tejas"
End Sub
Error Message:

MyProjectbit - but then obvously you might end up calling the wrong macro. Apparently this has something to do with "If you specify the document name, your code can only run macros in documents related to the current context — not just any macro in any document". - GSerg.Runwhen the macro name is not known at compile time, if you do know it at compile time, just call it directly. - GSerg