How to set up multiple child support wage attachment

How can I set up multiple child support wage attachments that will leave the employee a minimum net pay and allocate the disposable income equally among the child support payments.

The employee has three child support payments - all with different amounts.

The employee is supposed to have a weekly take home pay of 50% of his disposable income (gross minus tax).

The available 50% is to be divided equally among the three child support payments.

Example:  The EE has $500 net pay - therefore $250 of his net income is his take home pay

The other $250 is to be divided equally among all three child support payments = $83.33 for each support order.