Sandra is planning for retirement. She is currently $40$ years old, plans to retire at $67,$ and expects to live to $88.$ When she is retired, she would like to receive $$1200$ a month from her retirement account. She expects to earn $7\%$ interest while she is saving, and after retiring, she$$ll move her savings into safer investments, earning $5\%$ at that point. How much should she save each month between now and retirement to achieve her goal?