He wanted to know where to set the tree, not a specific node.
You should set the tree in MissionSetup, or at least outside of any loops. Remember how the function works, it takes 3 arguments.
1 - The ped's id to set the action tree of (gPlayer is the player's)
2 - The action tree (An action tree is the root of all action nodes in the style. So for example "/Global/P_Striker_A")
3 - The action file, which is where the actions (tree and nodes) of the style are located. All NPC styles are in the Act/Anim directory, and are just the title of the style with the file extension ".act". You won't find an Act/Anim folder with ACT (action) files in it, but the release version of them are in cat files in Act/Act.img. Luckily we don't really need it to find where the act files are because they all follow the same pattern of being in Act/Anim and having the .act extension. With finding nodes it may of been nice to have the ACT files but I guess we weren't that fortunate. So in short, "Act/Anim/P_Striker_A.act".
A complete call to the function could look like this: PedSetActionTree(gPlayer,"/Global/P_Striker_A","Act/Anim/P_Striker_A.act" and I would suggest putting it in MissionSetup, but make sure it is after AreaTransitionXYZ, because AreaTransitionXYZ must be the first function called inside of MissionSetup.
