If I understand you correctly you need to initialise some JS function/object before you call the Html.ToolbarControl helper? Couple of ways this can be done:
If you just want to have the JS inline then you can pretty much introduce it before you call it e.g.
<script type="text/javascript">
// JS here
</script>
@using (Html.ToolBarControl("Persona")) { }
If you have a master layout, introduce a new section for the head which will allow you to inject JS directly from your index.cshtml page (by default MVC already does this for you)
Layer.cshtml
<head>
@RenderSection("Head", false);
</head>
Index.cshtml
@using CrdToolBar;
@model MvcCrdToolBar.Models.Persona
@section Head {
<script type="text/javascript">
// JS here
</script>
}
@{
ViewBag.Title = "Index";
}
<h2>Registro de Persona</h2>
@using (Html.ToolBarControl("Persona")) { }