It's likely that in posting your question you are going to receive a number responses from attorneys like myself who are going to strongly suggest that you reconsider your decision to file chapter 13 without an attorney.
If your decision to go it on your own is based upon the belief that you cannot afford an attorney. Keep in mind that chapter 13 is designed to allow the debtor to incorporate of a substantial portion of their attorney's fees into the plan.
In this way, your payment for an attorney can be divided up into as many as 60 monthly installments. over the course of your chapter 13 plan.
Depending upon your individual financial circumstances and in particular the amount of your monthly disposable income, The minimum required monthly plan payments including attorneys fees could be the same amount of money that you would be required to pay without an attorney, the only difference being that your unsecured creditors would get more of a dividend if you do not include attorneys fees.
At minimum, if you haven't already done so, you should consult with an experienced bankruptcy attorney to find out what representation would really cost you in terms of your monthly plan payment, before you give up on the idea of hiring counsel.
In response to your question about whether or not you can send someone els on your behalf to file for you, I am unclear as to exactly what you are asking.
If you are referring to the idea of taking all of the completed schedules and forms along a certified check or money order for the filing fee and handing it to another person to physically bring to the court and file for you, As long as all of your schedules and forms have been properly completed and signed by you, then, You certainly can do that.
Alternatively, if you are asking whether or not another person can proceed on your behalf and accomplish certain tasks like attending a creditors meeting, that is clearly not acceptable. You must personally participate in all aspects of the completion of schedules and attendance at the creditor's meeting,