SSIS - Change Data Organisation

Hi,

here is my problem
i've a table in my database like this

Col1 | Col 2
____|______
aaa | 111
aaa | 222
aaa | 333
bbb | 222
bbb | 333


to insert data into a flat text file or another table
i would like to make a dataset like that :

Col1| Col2| Col3 | Col4
____|____|_____|_____
aaa | 111 | 222 | 333
bbb | 222 | 333 | NULL

the table is quite big, so i can't make it line by line

i would like to have a maximum of 12 column ( if there is more data than 12, these data should be ignored )

thanks for answering