Moving Rows into specific column...

Hi.. i have a problem here..
I need to move a number of rows, based on user input
in front of the first column, continuously until it 'flattens out' into one row..
And then do the procedure again for the next row
Kinda hard to explain.. maybe i'll use an example
using this matrix :

1	2	3	4	5	6
7	8	9	10	11	12
13	14	15	16	17	18
19	20	21	22	23	24
25	26	27	28	29	30
31	32	33	34	35	36

If user inputs "3", the matrix becomes :

1	2	3	4	5	6	7	8	9	10	11	12
13	14	15	16	17	18	19	20	21	22	23	24
25	26	27	28	29	30	31	32	33	34	35	36

The 2nd, 4th and 6th row is moved to row 1,2 and 3 respectively


If user inputs "2" the matrix becomes :

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36

2nd row is moved into the first row, then the third row is moved behind them
fifth row is moved into the fourth row, then the sixth row is moved behind them

If "1" then it becomes 1 row :

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36

Does it make sense?

I need to do this for a 1044x1044 matrix.. so i cant do it manually...

thanks.