Is it permissible to pay litigation costs in a case involving the recovery of orphans' rights using money obtained from interest?

Usurious gains are disposed of by giving them to the poor and needy, or by spending them on general public interests of Muslims that do not benefit a specific person, such as paving roads, building bridges, and constructing schools and orphanages. If the orphans do not have money to cover their expenses, then there is no harm in paying for them from usurious gains.