Steve,
I used the Citect software with an SqD model 400 processor back in 1990. Unfortunately all I can tell you is that it did work with the SPE4 port. It was so long ago and I have not done it since I can't remember how I did it. I know that there were no problems doing so because if it was I would have remembered that, you always tend to remember the problems.
I would call Citect or the Modicon help line, as I am sure you are aware that Modicon and Square D are all part of Schneider.
Sorry I could not remember more.