Sorry for not responding sooner, but I thought that this thread was over/closed.

One of the reasons why I'm not happy to use 3rd party add-ins is that our IT dept may not approve.
The other is that the file will be embedded in SAP and I'm not sure what's going to happen if I change/add it.

I have found a way to keep the file(-s) usable.
I will dig into your sugegstions as a learning experience and use it in other places (eg private)

Thanks for all your suggestions and contributions

Hein