How to enable copy paste of images, e.g. of Word documents

Hello together,

I just recently configured my first plone environment and site using the Bitnami virtual machine image for Plone.

I already made a few things working but still one thing doesn't work as it should.

Pasting images to a site that I copied directly from a website for example is working but if they are copied from a Word document or made with snipping tool or so I can't directly paste them into plone sites.
As far as I understand there should be a way with the built-in TinyMCE editor.

Can anybody explain how I can get it working?

Thanks a lot!

Best regards
Dominik