Hey @Dimitris_Derm.,
The example py_msc_licensing shows you how to change the icon of a node at runtime. The example uses this to change the icon of unlicensed nodes and the trick is to listen for the message MSG_GETCUSTOMICON.
The example py_obj_assetcontainer shows you how to place icons in cycles (Cinema slang for drop downs). The trick is to set the label of the cycle item to "{Label}&i{IconID}&", e.g., "Cube&i5159&" would display the cube icon next to the word "Cube", because 5159 is the cube object icon id. You can do this both in resource files and dynamically as the example does it.
Cheers,
Ferdinand
