calling rfc function module through excel

Hi,

I  am trying to call rfc function module from excel . all parameter passes successfully , but when calling rfc function module it gives false result.

below i am sending my code used for rfc communication with excel

    Set MyFunc3 = R3.Add("YHR_SEND_EMAIL")

    Set P_PERNR = MyFunc3.exports("I_PERNR")

    Set FILE_PATH = MyFunc3.exports("I_FILE")

    P_PERNR.Value = Row1("PERNR")

    FILE_PATH.Value = TheFile

    Result = MyFunc3.CALL

  rfc function module name :YHR_SEND_EMAIL

import parameter :  I_PERNR,  I_FILE

    when i try to execute these lines of code , it returns false value in result variable. and enters in else condition.

please help me.