I created Civolopedia entries for units in a scenario, but now I can't figure out how to make pediaicon thingies for the units.

I have created a folder for the scenario containing Civolopedia_CEC.txt and Pediaicons.txt.

Thanks in advance!

I have a program that will create the pedia icons text entry for you. Just check my sig

I have created a folder for the scenario containing Civolopedia_CEC.txt and Pediaicons.txt.
You'll need to rename the first file to Civilopedia.txt, the _CEC bit is added when you generate a civilopedia from the CEC utility. It will not be recognised in the game unless you rename it.