Set (user defined) metadata for downloaded news automatically

[mjost]

Hello,

I'm using a Kobo Glo reader.
This supports "Shelves" which are reflected as user defined metadata in Calibre.
(This works nicely - thanks !)

Now I would like to have my news downloaded by calibre automatically put on the correct shelve(s) - boiling down to set this metadata on download.

E.g.:
I'm using the recipe for "Süddeutsche Zeitung". Whenever this is downloaded, I would like to find it on the shelves "News" and "SZ". Currently I have to set this by hand - rather annoying....

I found that I can "Set additional keywords" on the "Advanced" tab of the recipe. But - to my understanding - I would need to set a specific User defined Keyword to get what I want.

Is this possible ? How ?
Feel free to point me to matching resources in the forum or the web.
(I tried to search for it, but couldn't find it...)

Thanks

Martin