Well, the normal way to do your project is to get your design right. It seems that you started off building a prototype.
The best way is to convert the existing application into modules - into separate entities. I am not sure if you know about Object Oriented Programming. Merely converting a couple of files into a DLL might not be a good idea. You might want to look at your current application long and hard and find out the various links and relations between different forms.
Once you know that, you can use OOP design methodology to rehash your application. This might take some of your time but in the long run you surely would have a better control and maintenance would be much much easier. You will be able to plug in and unplug object modules at will.
You may ask me if you have any more questions.