generic datasource function module logic req:

HI TEAM,

i need to build a function modue  for text datasource based on product hierarchy my requirment is that i need to split product hierarchy( prodh) into three datasources with its text so as to create a text datasource.

ex : if my product hierarchy is 18 digitsi need to split it into three .  if prodh =020000001500000001.

i need 02000  first 5 chars represent my project  . 020000001500 first 10 represent my tower no and the total 18 digits represent my floor no.

i need to build three text datasource for each and the logic is

if mara-matnr = mvke-matnr pick prodh from mvke and its text description from t179t table. for each datasource .please provide function module logic for generic datasource.