reading values through the usartread function

Question

if (val == 3) {
           //USARTWriteChar(USARTReadChar());
        char point = USARTReadChar(); //USARTReadChar
        buff[y] = point;

       if (point == 0x0D) {

            buff[y] = '\0';
            buff[y] = END_STR;
            int c = atoi(buff);
            itoa(aux, c, 10);

I need to communicate with the PIC through the serial port and the moment I write a whole number with two or more digits on the computer keyboard, it should return the table of that same number