Urgent help Plz - Combination of Valueas from Internal table

Hi Abap Gurus,

I have a requirement, can any body please help me.

Requirement:

I will get Target Quantity, which need to be fulfilled by the different quantities i am having in my internal table.

Example: Target Quantity -120

The records in internal table :

10

30

70

25

50

85

15

So i have to pick minimum number of quanitites from the ITAB which is equal to target quantity 100.

here we can give 70 & 30 for 100.

In Abap, how can we check all the combinations of values...Is there any best approach to handle this kind of requirement? please help me..this is very urgent requirement.

Thanks,

Nanda