>... how do you 'apply'; the curve in photoshop?
In the upper menu bar of PS click on Image and follow the menus:
Image>Adjust>Curves.
In the Curves box click on the upper right button to reveal a menu that includes "Load Preset." Then you have to find your folder with that curve.
I set up a folder, "PS Curves" in My Documents for them to be sure my various backups pick them up. I have a sub-folder for every printer and inkset. The curve you're using is rather generic for all gray gamma to QTR space adjustments. (But it's not a perfect adjustment for all situations. It's more empirically set for my lighting, etc.)
You have to remember that you don't want to edit with that curve applied. Don't wreck your master working files. Either have the curve on a layer or (as I do) make a "QTR Printing" copy of the file for prints as you go and then trash them.
Paul