converting string field to type P and increasing length size in dynamic internal table

Hi,

I am working on dynamic internal table report list where I am facing data type and length size issue in the amount and quantity fields. For dynamic internal table, I am using class cl_abap_structdescr and calling CL_ABAP_OBJECTDESCR->GET_STRING  for appending field names. this leads to data type is string and the length is fixed based on the values. Due to this my Net amount and Quantity values are not translating CURR types and not able to write the value to Right-Justified in the output.

Output ex like;

Net amount                                                                  Quantity

305623.00   (to be 305.623,00 & right-justified)   25.00 (to be 25,00 & right-justified).

Please guide me how to fix this issue by changing the field type to P (Currency and Quantity type).

thanks.