Hi, @wp!
Thanks for your reply. In fact, I do not want a 'calculated field' - this was mistakenly taken from an example I found here on the forum. I just want to add a field at runtime.
The example pointed out by @korba512 seems to be similar to what I need, but as I wrote in my previous reply, I got compiler errors because of a seemingly unrecognized type.
With best wishes,