Sorry I am a bit late coming back to this thread.
It's been a while since I set up my PDN curves, but as I recall I just transferred the three color values from the PDN spreadsheet to the PWP curve text file. In PS, you have to go in and enter the values within the program, and can use only a limited number of values. I found the PWP approach easier to use.
The PDN system is definitely PS-centric so I was a bit concerned I'd have to spring for the cost of PS. However, once I had read through the tutorial, done the tests and entered everything into the spreadsheet there was no problem.
The only issue, as I recall, was that all of the files you print are .psd files, so you need some sort of software that can print those files. I had an old version of Elements that took care of that.