I dont think going via the power socket and the regulator would be a good idea.
Does anyone have one or anyone knowledgable about the rugght connection please? I guess I could use the Vin and gnd pins but that would preclude a sheild.
Well the backpack generates a regulated +5vdc output, so you only have three choices of where to wire it to the arduino:
Pins 2 & 6 of the ICSP connector pins
+5vdc and ground pins on the shield power connector strip.
Take a spare USB cable, cut off the PC end, locate the +5vdc and ground wire from the four wires and wire to the backpack's +5vdc/ground output. Then just plug the USB connector into the board to power your arduino.
Thanks retrolefty that was fast. Yeah I dud sone research online after looking closely at the photo but I just wanted to check it was a redo able approach to use the ICSP header. I know a pro framed would use those pins to power the board so it's no different really.