SelectPlayer MP compatible

Hi i want to create a player model choosing system wich is activated by GUI OnButtonClick.

i know how to create basic GUI but i dont quite understand how to make the CreateUnit works.

i want to make that script will create unit for example "Soldier_Medic_PMC" somewere (not important where), SelectPlayer the newly created unit and delete the old player unit and this needs to work in multiplayer and very important is that this model will stay with player after respawns. As well the player could access the GUI to later change the model again. Yet i tried it using addaction:

_caller = this select 1;
_id = this select 2;
_unitt = createUnit ["TK_Aziz_EP1", getPos _caller];
_caller SelectPlayer _unitt
_caller removeaction _id;

but it doesnt work. any help would be appreciated.

---------- Post added at 19:12 ---------- Previous post was at 19:10 ----------

I want to make this because for example "Soldier_Medic_PMC" has the ability to heal wounded players.

Always read the command's description/syntax first.

Object = [b][color="#FF0000"]group [/color][/b]createUnit [type, position, markers, placement, special] 

_caller = this select 1;
_id = this select 2;
_unitt = (group _caller) createUnit ["TK_Aziz_EP1", getPos _caller, [], 0, "NONE"];
_caller SelectPlayer _unitt
_caller removeaction _id;