How to modify what is shown in the gvnix loupe field?

I am working on a project with spring roo and with gvnix, the question I have is about the loupe field, I already know how to change what is shown in the list of search results, concatenating the fields of my entity that I want and calling them with the tag onDrawFunction .
Now when I select one of the results of the list I want to be placed in the input as it appears with everything and the concatenation but only the first field that is the default appears

This is the field loupe code in my create.jspx :

<loupefield:loupe  additionalFields="nombre,apellidoP,apellidoM,curp" caption="nombre" controllerPath="dictamens" field="perito" id="c_com_avance_periciales2_domain_Dictamen_perito" listPath="peritoes/list" mode="create"  searchField="alert()"  onDrawFunction="onDrawNombrePerito" path="/peritoes" pkField="id" z="user-managed"/>

this is my code in the loupe-callbacks.js

function onDrawNombrePerito(oData){
   return oData.curp + " - " + oData.nombre + " " + oData.apellidoP+ " " + oData.apellidoM;
}

Will there be any tag or function already defined for this operation? or I will have to modify the javascript that are already created automatically by the gvnix framework and thus tell the js what I want to appear in the input when selecting one of the results