Yes you can. You can transfer from any GBA game to any 4th generation game by using pal park. This only works if you have a DS lite or an original one
First put your GBA game on the bottom slot of your DS and your 4th gen game on the top slot.
Then you have to go to the main menu of the 4th gen game
Then you go to scroll down until it says migrate
Go through the instructions and choose the Pokemon to migrate
Go to the 4th gen game and go to pal park which is in route 221 in sinnoh games and fushia city in HG/SS and catch the Pokemon there.
Source: http://bulbapedia.bulbagarden.net/wiki/Migrate
