To make this formula you need some Eucylypt charcoal and some strongly brewed black tea.

Carefully sterilize all utensils, bottles and teats by boiling.

Mix:

3oz black tea
5oz cows milk
1teaspoon finely crushed charcoal.

Feed the Joey as much as it wants every 2 hours right around the clock, until it starts to forage grass.
Then feed every 2 hours through the day and every four hours at night.

Make sure to keep the Joey warm at all times, simulate the conditions of the Kangaroos pouch as closely as you can.

Tiny hairless Joeys need a lot of humidity in the artificial pouch to survive.