Is there utility to convert Cubase FXP or FXB files to Logic PST format, but for PC platform?
Thanks

There's no need for one, Logic supports the FXP/FXB format directly - though if you're not using Logic 5.x, there could be problems if the patch/bank has a large number of parameters.

Do this : if there is a subfolder with the same name as your plugin present in Logic's Presets folder, place your FXP/FXB files in there. Otherwise, create a subfolder in the Presets folder with the same name as your plugin's .dll file.

Now when you load up you plugin in Logic, click on the "down arrow" which you normally use to access your PST format presets and the FXP/FXB files you placed the the Presets folder should appear.

Hope this helps.