Expense Allocation Basis Percentage(value) calculation

Hi,

we have a requirement i.e., want to enter the Expense allocation code cost Amount/unit for each code in "Allocation Basis" form rather entering the percentages(Value).

And accordingly the expense allocation code percentages(value) by item needs to be calculated.

As per my understanding this requirement can be met with following...

1) Capture the Allocation code cost Amount/unit in "Allocation Basis" screen but didn't find any extra column or DFF in this form.

     so may be needed to "create a custom form" to capture these figures.

2) Create a procedure and concurrent program to call this procedure to calculate the Allocation percentage(value) and update percentage(value) in the "Allocation Basis" form.