You need it to open a door to beat Team Rocket and that's all you can do with it.
The card key in Pokemon Heartgold and Soulsilver is located in the Goldenrod Underground.
In order to get the Card Key in "Pokémon HeartGold," you need to get to the Director who will be in the Underground Tunnel in Goldenrod City after Team Rocket has taken over the Goldenrod Radio Tower. The Director will give you the Card Key which will open up a Card Key door in the Radio Tower which will assist you in defeating Team Rocket.
in the basement of the galactic warehouse in veilstone city
If I remember correctly, once you beat Petrel, he gives you a key to get to the director, who is in the underground. The director will give you the key card.
The shutters are in the Radio tower. You need to go to the third floor and go to the sealed door where that lady is standing and use the key card.
To the game card.
you cant
you only get the card in heartgold and/or soulsilver
put the key card in the hole at the eye scan and key card lock is
Get the Radio Card from the Radio Station.
im not sure if there is a thing
No, not enough space on the card.