I have some functions that export modules and re-import them. It is configured now for PPT but was hacked together from Excel functions that I found. There is also a way to use VBA to write VBA. Both are fairly advanced though. Probably both sets of functions are available here:
http://www.cpearson.com/excel/vbe.aspx
However, that's probably overkill. This is probably your best bet, to use a popup instead of a VBA msgBox.
Sub Test()
Dim wdApp As Object
Dim shl As Object
Set wdApp = CreateObject("Word.Application")
wdApp.Visible = True
wdApp.Activate
Set shl = CreateObject("wscript.shell")
shl.Popup ("Hello, world!")
Set shl = Nothing
Set wdApp = Nothing
End Sub
See also here for more detail about how to control it's timeout/etc.
Whats the best way to display a message box with a timeout value from VBA?