Cut .csv to pieces and save as .csv

[BruderKellermeister]

Thank you all very much for thinking about my problem! That is very helpful to me!

I'm sorry I didn´t get it clearer:

I have 1 big list with headers.
To make things complicated, there are 2 samples per tree with the same header. Like displayed below - treenumber 578 has two columns.

Name: HappyTrees.csv

"Date" | "578" | "578" | "579" | "579"
------------------------------------------------
 2012  | 7,34 | 4,34 | 9,65 | 5,34
------------------------------------------------
 2011  | 5,23  | 4,75 | 8,63 | 3,46
------------------------------------------------
 2010  | 3,45 | 3,78 | 6,34 | 5,82
-----------------------------------------------
  2009 | 5,83 | 6,28 | 8,24 | 5,42


What I need:

1. Name: 578a.csv

"Date" | "578" |
------------------------------------------------
 2012  | 7,34 |
------------------------------------------------
 2011  | 5,23 |
------------------------------------------------
 2010  | 3,45 |
-----------------------------------------------
  2009 | 5,83 |



2. Name: 578b.csv

"Date" | "578" |
---------------------
 2012  | 4,34 |
----------------------
 2011  | 4,75 |
---------------------
 2010  | 3,78 |
---------------------
  2009 | 6,28 |



3. Name: 579a.csv

"Date" | "579" |
----------------------
 2012  | 9,65 |
----------------------
 2011  | 8,63 |
-----------------------
 2010   | 6,34 |
---------------------
 2009  | 8,24 |


4. Name: 579b.csv

5. Name: 580a.csv

6. Name: 580b.csv

........... and so on.........  and so on.........