Yes, you need to make an EasyPLC external driver, then use the analogic I/O to manage the data stack. I recommend you to read the tutorial How to Make an EasyPLC Driver for EasyPLC, there you will find more documentation.
Any way I remember time ago I make and external driver that was using the DDE protocol to communicate with third party software, when I'll have more time I will create a tutorial about this matter.
Regards.