OK i have only done the back of the card for heart and joker, but to do it all i did was put it in
mods is Aalis folder and DK is the name of the folder inside mods which DLBP and i use for mods. And like i said, if you edit the ff7_opengl.cfg and turn on the line "Show Missing textures" then play the battle and it should say what the PNG's need to be called, in this case your PNG "ekad.png" needed to be renamed to "CARD_00.png"
so the full path for me is
C:\Program Files\Square Soft, Inc\Final Fantasy VII\mods\DK\Magic\FF7\DATA\BATTLE\special\heart1\CARD_00.png
and that is just for the back of the hearts card, if you want other cards you modify where it says heart1 to for example Joker1.
hope this helps.
EDIT:- after switching on "Show Missing textures" you need to read the App.log to see the filenames.
and now i am off to sleep, its midnight here