Implementing Front Controller pattern

I've been trying to implement a Front Controller on a VBScript (ASP Classic) based system for a couple of days. I come from a ASP.NET MVC and Java background, where MVC implementations are kind common and mostly done by existing frameworks. On VBScript, however, there's almost nothing done in this area, so it is the reason why I'm trying to do it by myself. I used this and this article as a guide on how to implement it.

I believed at first that I'd need to define some constant parameters for each request, so I created 3:

class_command  'which command responsible to execute the correct class handler
action         'which method of the class handler to execute
action_params  'which parameters the action will need

Next, I defined a generic controller handler for treating the request:

Public Function Controller_Handler(action_params)

Its task is to extract the constant parameters (class_command, action, action_params) and treat any errors (I'll add later a filter to process it) that might come like absence of the constant parameters or authentication problems.

But soon I realized a problem: how will the handler know which command to call, since the request is a string? I can't simply converting it to class using reflection, because VBScript (I think) doesn't have a reflection library or built-in feature.

So I thought I could create a Switch Case like this:

Select action_Params.Item("action_params")
  Case "command_A"
    ' Call Command A
  Case "command_B"
    ' Call Command_B
   .
   .
   .
  Case "Command_X"
    ' And so on
End Select

But that would kinda procedural way to do it. Next I thought of creating a XML file which would map all the commands and other stuff.

So my question is: is this a good way of implementing a Front Controlller pattern, considering VBScript limitations? If not, could you provide a guidance (hopefully with some example, even a simple one) on how can I do it?

Solution

Moving from classic to .net/mvc I can share what I did in classic asp to try to emulate this behavior as closely as possible without making it too much of a maintenance issue.

Using URL Rewrite in IIS are my routes. I usually just make one route and direct/rewrite all inbound requests to one controller.asp page to simplify things and not have a bunch of rules and controller redirects directly in my URL Rewrite settings for maintaining it easier (for me).
Using Request.ServerVariables("HTTP_X-ORIGINAL-URL") in controllers.asp you can grab the actual URL that was entered, which return something like.. /real/url
In controllers.asp programatically call the view based on the entered url using Server.Execute("view1.asp")
I have one class file called routes.asp that is included in each model/class file, and helps me gather the URL properties oRoute.GetPath_FirstDirectory() and so on. The model/class file then uses this data to create its property values that can be consumed by the view. Using CLASS_INITIALIZE in each model/class to populate itself from the route/url, or it could also be done directly in the view.
In the respective view I include my class/model file (if even needed) using  then simply open Set Model = new cModelClass to initialize and start using it in the view. I don't include the class in the controllers.asp because the view will not inherit any of the variables from controllers.asp when using Server.Execute() to the view. So I include it directly in the view.

Error handling can be at multiple levels here, but ideally its in the controllers.asp. Specific error handling is usually at the actual model/class CLASS_INITIALIZE to avoid redundant use of the class in the controller, since it's already going to be initialized in the view.

Now this is not exactly what goes in in .Net mvc, but it's the best way I've come up with, and easiest to maintain for me. Maybe others have other implementations, but this is mine and solely based on my experience. And so far, it's been working out pretty well.