In the TurboPrint online manual, it was written to position the center of the CD that way:
Canon (e.g. i865,i965,PIXMA):
2.55 inches / 6.5cm from the left page edge
5.75 inches / 16.6cm from page top
Epson (e.g. Stylus Photo R200,R300):
2.95 inches / 7.5cm from the left page edge
2.65 inches / 6.75cm from page top
Actually the Epson settings didn't work correctly for the Epson Stylus Photo R220. I had to position the image at 5.25 inches instead of 2.65 inches from the page top for the image to be printed at the good position.