You can't deposit money into a 401(k) ever, it can only come from payroll withdrawals. Are you eligible to make regular IRA or Roth IRA contributions?
Can you give more details about the lawsuit and the payment? It seems to me that they payer should have put the money back into your 401(k) for you, if that was the issue. I rather expect this is going to be a taxable lawsuit settlement and there isn't any way to defer the taxes until later, but I could be wrong. @dmertz
