Warband Add Horse whistle to native ?

[Mballday1]

Hi all,

 

I want to add the horse whistle to the native version of the game to fetch my horse. I've looked for a mini mod on the subject but I've come up short. I know there are a few bigger mods that have the feature but I really just want to add this to native. How hard is it to add the feature? I know how to do some basic modding to the game but thats about it. Thanks for any info.