Try using the default values to get the spring created and then edit the spring part file and use the variables/values you want. This worked for me but I did not have all the parameters known, only the diameter.
Following up on your advice, I first opened edit mode from pathfinder right click menu relating to spring file. I have used this before to edit spring length and number of coils. Checked wire diameter and discovered many more options when I opened the wire diameter drop down box. ???! Why were all those diameter options not available when I first opened compression spring designer?
Oh well - no problem. I got where I needed to go. Thanks, Ronnie, for help finding the right direction for the solution.