How best to add Plugin Capability to a Delphi program

I am looking to add the capability for users to write plugins to the program I have developed in Delphi. The program is a single executable with no DLLs used.

This would allow the user community to write extensions to my program to access the internal data and add capabilities that they may find useful.

I've seen the post at: http://stackoverflow.com/questions/8140/adding-plugin-capability but its answers don't seem transferrable to a Delphi program.

I would like, if possible, to add this capability and keep my application as a single executable without any DLLs or additional modules required.

Do you know of any resources, components or articles that would suggest how to best do this in Delphi, or do you have your own recommendation?