I transfered my Manaphy from my R4 to a retail version of diamond so should work. I used the following instruction, just remember both games need to be from the same region, none of this Euro ranger and US diamond, must both be E or U.
Step 1: Access Ranger Net after finishing the DS game Pokemon Ranger. When you see ranger net on your main menu, click on it.
Step 2: Your bottom screen will show “Play a special mission.” On your Nintendo DS press the top Right trigger, the X Button, and left on your directional + pad, all at the same time.
Step 3: You should now see a screen that says ” ‘Enter the password’ has been added.”
Step 4: Tap the touch screen, and wait as the game saves.
Step 5: After the game saves, tap the screen again, and a new menu will come up that says “Enter the password.”
Step 6: When you click on the password menu, you’ll be allowed to “Enter the password”!
Step 7: Enter the password with capital letters:
* In America / Canada / Australia it is P8M2–9D6F–43H7
* In Europe it is Mg35-Cpb8-4FW8 says www.manaphy.eu
Step 8: You’ll see special message that says the mission is active “You’ve been assigned the special mission: ‘Recover the Precious Egg’ Play it from the Ranger Net menu. Please turn off the game.” Turn off the game.
Step 9: Turn on the game again. At the menu screen, access Ranger Net and you’ll see an option to “Play a special mission”. Select it.
Step 10: The mission “Recover the Precious Egg!” appears. Select it.
Step 11: You did it! Congratulations, now start the mission to get the Manaphy Egg. Once you’ve found the Manaphy Egg.
Step 12: To get your Manaphy egg from Pokemon Ranger to Pokemon Diamond or Pearl you’ll need two DS systems. This will only work if the DS systems are set on the same language AND if both Pokemon Ranger and Pokemon Diamond or Pearl are the same version (meaning they have to be from the same region or country for the transfer to work!)
Step 13: Put Pokemon Ranger in DS system 1. Put Pokemon Diamond or Pearl in DS system 2.
Step 14: Turn on DS system 1 with Pokemon Ranger. Go to the “Check Egg” screen and click on it to go to your Manaphy Egg and touch it so you see a “Send” button. Touch the “Send” button.
Step 15: Turn on DS system 2 with Pokemon Diamond or Pearl. Press “Start” on the title screen and the game will tell you you’re picking up the signal from DS system 1. Then follow the on-screen instructions the game gives you.
Step 16: Eventually you’ll have to hit a “Transfer” button on Pokemon Ranger and the Manaphy Egg will be sent to Pokemon Diamond or Pearl.
Step 17: Now that you’re finished with the transfer, start Pokemon Diamond or Pearl game.
Step 18: Make sure you have an open slot (five or less Pokemon) in your party.
Step 19: Go into any PokeMart and talk to a man wearning green. He’ll then give you the Manaphy Egg!
Step 20: Go outside and take 2560 steps (or ride your bike) then go back to the PokeMart and a Lv. 1 Manaphy will hatch! Congratulations!