Hi Sayantan,
Can you clarify the requirement, the condition value if you want to reference can be done by routine in the alternate calculation type routine.
Where Just you have to save the condition value to a subtotal and reference the same KWERT in the routine.
Or you can use from field for the reference condition type.
If you want to make it statistical in billing you can also write a routine for the same.
Thanks!
Amlan