Client specific code in separate dll?

Hi,

One feature in my VB6 application works fine for 99% of the clients, but in some cases a custom set of calculations is required. Unfortunately there is no way to implement this in a generic way through the UI. However, I don’t want to end up with a whole series of client-specific versions, as this will become a maintenance nightmare very quickly.

So I thought of the following approach:

If there is a need for a client-specific routine, it is created in a separate dll that is distributed to that specific client only. At application startup we check for the existence of the dll, and set a flag. When the standard routine is called, it checks for the flag, and based on that either runs the client-specific routine or the standard routine. The dll can have the same name for each client, as it will be distributed separately.

Now this is the first time I’d be breaking out code in a separate dll, I have some questions:

1. Based on your experience, is this a good approach, or do you recommend another?
2. Are there specific things to be aware of when taking this approach?

Looking forward to your ideas, suggestions, etc.

Thanks in advance!

Erwin