Modding Help: How to give Vassals troops?

[rsanagustin]

How do you give allied lords (or any lords) the option to give them troops? For more of a challenge. Can someone tell me what to modify or script it? I'd appreciate the help. This is for with Fire And Sword

 

[arkanis]

As the Tsar I can give troops to my people. (Tsar=king of the muscovites)