Load a modal with its controller as a service - angularjs

Question

I am trying to create a factory that loads the html template and then compile the html with the newly loaded controller...
app.factory('$modal', function ($templateProvider, $compile, $ocLazyLoad){
return {
open: function(modal) {
$ocLazyLoad.load([
'modals/'+modal+'.html',
'modals/'+modal+'.ctrl.js',
]).then(function() {
// How ?
})
}
}
});
I also tried to get the html via $templateProvider after loading the controller with ocLazyLoad and then using the $compile service. The problem beeing at any time that the controller is not available !
In the config, I tried the following:
app.config(['$stateProvider', '$httpProvider', '$locationProvider', '$urlRouterProvider', '$controllerProvider', '$compileProvider', '$filterProvider', '$provide', '$ocLazyLoadProvider',
function ($stateProvider, $httpProvider, $locationProvider, $urlRouterProvider, $controllerProvider, $compileProvider, $filterProvider, $provide, $ocLazyLoadProvider) {
app.controller = $controllerProvider.register;
app.directive = $compileProvider.directive;
app.filter = $filterProvider.register;
app.factory = $provide.factory;
app.service = $provide.service;
app.constant = $provide.constant;
app.value = $provide.value;
}]);
The idea being that I should be able to declare a new controller that just got loaded by using angular.module('myApp').controller(.... No success either.
I am stuck at this point, has anyone done that before ?