Here is a remix of the model created by @josteb
If you have already printed the holder and only need a longer screw, you can print only the screw and delete the rest from the objects in the slicer.
I have "extended" the screw in the slicer.
The screw is now approx. 57mm long so that the holder can be attached to a table with a thickness of >7mm.
To do this, I simply cut the screw in the centre in the slicer -> copied the upper part and simply placed the copy on the existing screw so that the thread looks "seamless".
No Rocket-sience, but its working.
i made it out of ASA as a trial with a new material because im a beginner but you can use whatever you want.