[R] little manipulation on data frame

[N Dey]

Dear all,

I have data like 3 coulmns and many rows. Each entry
is less than 10.

Example
	x	y	z
1	5	3	2	
2	3	7	8
3	8	9	5
4	5	4	6
--------------------------
---------------------------

I have to sum entries of each coulmn (seperately) till
it be 10. This i have to start for each row. And I
want to assign no. of rows needed including that row
too(it to be 10 or 10+, the moment it exceeds 10, i
need to stop and count the no. of rows)in additional
coulmns say N1 (corresponding to coulmn x), N2 (y) and
N3 (z).


I want my new table like

	x	y	z	N1	N2	N3 
1	5	3	2	3	2	2
2	3	7	8	2	2	2	
3	8	9	5	2	2	2
4	5	4	6	depends upon next row


If anybody knows it, please help me.

Thanking you.

Best regards,
N. Dey.