A complex trust only consists of rental property that has a rental loss carryforward.

The beneficiaries took distributions for $10,900. They say that there is $4,800 remaining principal balance and expect that $4,800 of the distributions will be allocated to principal.

However, the total $10,900 amount is being allocated to the beneficiaries. How do I allocate part of the $10,900 reported on 1041 sch b line 10 to corpus? 

Otherwise, the total distribution is counted as income to the beneficiaries and reduces the rental loss carryforward by $10,900.

Is there not a way in PS to allocate distributions to corpus?

Thanks.