is that the one you are talking about ?
http://cgi.ebay.co.uk/ws/eBayISAPI....175363&ssPageName=STRK:MEWAX:IT#ht_500wt_1156
I have one of those for my old primera. Programming look simple enough :
KEY FOB PROGRAMMING
NISSAN
SYSTEM DESCRIPTION
The Central Door locking is controlled by the Multi-Remote Control system which controls
the door locking, door super locking and hazard reminder. When the doors are locked and
unlocked the unit flashes the hazard lights once for lock and twice for unlock.
A maximum of four remote controls are allowed to be programmed.
ALMERA
ALMERA TINO
PRIMERA
MAXIMA
MICRA
SERENA
VANETTE CARGO
TERANO II
Ensure all the doors have been unlocked, either by using a good transponder key or remote
control plip key.
Procedure
1. Turn the ignition switch from Position 0 to ON 6 times within 10 seconds.
2. Then turn ignition switch to OFF position. Leave key in ignition switch.
3. After 2 seconds, the system will enter programming mode and will flash the warning
lights twice.
4. Press and HOLD the unlock button on the Plip.
5. While pressing the unlock button, press the lock button 3 times.
6. Release the unlock button.
7. The warning lights will flash once to indicate successful programming.
8. Repeat procedure 4 to 7 for up to 4 plip key’s.
9. When completed turn ignition ON, and the warning lights will flash 2 times.
10. Remove key, and check all plip key’s for operation.
NOTE : The programming mode will stop when either the ignition is switch ON, 4 plip keys have been programmed or no input signal either from the switch or plip keys has been received for 120 seconds.