Hi @PeSch,
With Graph Builder, you can also do it by right clicking. Then, from the menu choose Points > Set Shape Column ...
Or with other point (marker) graphs, you can right click. Then, choose Customize ...
Then, with the Marker panel, click Set Marker Draw Column ...
... then, choose the expression data column.
~John
Pasting images isn't working for me in community, so my image was missing... Right-click on the bottom-left columns panel instead of column headers on the top.
Right click on column name on the column listing and you can find "Use for marker".
Dear Jarmo,thanks for the suggestion - unfortunately I do not see it using the right click:
Thanks - yes . there it is easily visible.
Thank you,both options worked - but I would never have found them without your help - I think I even tried option 2, but then gave up.