Hi Rajaram,
You can do it in the following way:
X - sender CC
Y, Z - receiver CCs
In first assessment segment allocate fixed amount of $30 from X to any Cost Center (e.g. A)
In second segement allocate remaining value (Total Admin Costs - $30) to receivers Y and Z.
In third segement allocate back $30 from A to X.
With this option you do not have to recalculate SKF values based on total costs.
Regards,
Szymon