Module Pool Problem

Hi all,

I am creating one module pool program,in which i am using some I/O fields and one table control like standard T-codes (VF01....) ...

Now i am creating search help on one of the field in table control

( on<b> Bill Number</b>).

But i want to make it dynamic.

Means in one of the I/O field i am giving Form Type (like 'C','H' or 'F')

now in table control <b>Bill number</b> of the Tax code of that form type should come.

means if my Form Type is <b>'C'</b>.

and its Tax codes are suppose <b>'VF'</b> and <b>'VL'</b> so when i give 'C' as form type and then i press F4 on Bill Number, it should display Bill Number of 'VF' and 'VL' type.

and one more problem is that 'C' , 'H' and 'F' are not save in my dbtable ,only Tax code save in dbtable (RBKP - MWSKZ1) so i have to put condition for tax code..

So is that possible?

Thanks in advance....

Its quite urgent.....