Need to insert German characters regularly

In one of the earlier versions of DW, I was able to set-up a new tab in the toolbar at the top, to insert custom special characters from the toolbar, into my DW docs.

Somewhere I found instructions how to set this up, including making special button icons etc. Unfortnately Ihave no record of how it was done, and I have forgotten the process.

Is there an extension anywhere for the same purpose? I need to regularly insert German characters into documents.

Thanks
Peter