If you look in the "export_units.txt" in the text folder using Notepad or something similar, just look up the name of the unit using the "Find" feature. In the {}, you'll see the code name.
For example, if you want a Alamanoi, the entry would look like:
Code:
{Alamanoi_descr_short} Mercenaries from northern-central Europe, in the employ of the Roman Army, equipped with zweihanders and mail armour.
{Alamanoi_descr} Quality: Superior.\nType: Early Professional.\n\nThere are two types of mercenaries in the Roman army. Most common are the irregular mercenaries hired for specific periods or campaigns, and secondly are those that are kept on full time. The Alamanoi belong to the former and are made up of Germans and Flemings. Hailing from Northern central Europe, it is not surprising to see these warriors armed with mighty Zweihanders.
{Alamanoi} Alamanoi
The phrase in Blue will be what you type in