You can use the ATTR_EJECT_AFTER print attribute in order to combine multiple printouts in the same page. By setting that attribute to 0 (using SetPrintAttribute) you can call PrintPanel or PrintCtrl multiple times. When you're done printing, simply set ATTR_EJECT_AFTER back to 1, and the print job should be sent to the printer.
The number of times you have to print will depend on what else is in your panels. If you want to print each panel as it appears on the screen, you can just call PrintPanel a couple of times. If, on the other hand, your panels include other controls that you don't want to print, then you will have to call the PrintCtrl function 4 times, one for each of the controls you want to print.
You will also have to play around with the ATTR_XOFFSET, ATTR_YOFFSET, ATTR_PRINT_AREA_WIDTH, and ATTR_PRINT_AREA_HEIGHT attributes in order to place your panels or your controls exactly where you want them.
Luis
NI