SparkFun OpenScale Load Cell Calibration

I have a load cell connected to the SparkFun OpenScale and I am trying to alter the code used to calibrate the load cell. The OpenScale has a built in calibration function shown below:

//Gives user the ability to set a known weight on the scale and calculate a calibration factor
void calibrate_scale(void)
{
  Serial.println(F("Scale calibration"));
  Serial.println(F("Remove all weight from scale"));
  Serial.println(F("After readings begin, place known weight on scale"));
  Serial.println(F("Press + or a to increase calibration factor"));
  Serial.println(F("Press - or z to decrease calibration factor"));
  Serial.println(F("Press 0 to zero factor"));
  Serial.println(F("Press x to exit"));

  delay(3000); //Delay so user can read instructions

  long lastChange = millis();
  int changeRate = 1;
  int holdDownCounter = 0;

  while (1)
  {
    scale.set_scale(setting_calibration_factor); //Adjust to this calibration factor

    Serial.print(F("Reading: ["));
    Serial.print(scale.get_units(setting_average_amount), 4); //Show 4 decimals during calibration
    //Serial.print(scale.get_units(setting_average_amount), setting_decimal_places);
    Serial.print(F(" "));
    if (setting_units == UNITS_LBS) Serial.print(F("lbs"));
    if (setting_units == UNITS_KG) Serial.print(F("kg"));
    Serial.print(F("]   Calibration Factor: "));
    Serial.print(setting_calibration_factor);
    Serial.println();

    if (Serial.available())
    {
      //toggledLED(); //Blink serial indicator

      //Check to see if user is holding down the button
      long delta = millis() - lastChange;
      lastChange = millis();

      if (delta > 500) //Slow, increment just 1 and reset holdDown counter
      {
        changeRate = 1;
        holdDownCounter = 0;
      }
      else //Medium 10 and increment counter
      {
        changeRate = 10;
        holdDownCounter++;
        if (holdDownCounter > 25)
        {
          holdDownCounter = 100; //Don't let this get too big
          changeRate = 100; //Change faster
        }
        else if (holdDownCounter > 10)
        {
          changeRate = 100; //Change faster
        }
      }

      while (Serial.available())
      {
        char temp = Serial.read();

        if (temp == '+' || temp == 'a')
          setting_calibration_factor += changeRate;
        else if (temp == '-' || temp == 'z')
          setting_calibration_factor -= changeRate;
        else if (temp == '0')
          setting_calibration_factor = 0;
        else if (temp == 'x')
        {
          //Record this new value to EEPROM
          record_system_settings();
          return;
        }
      }
    }
  }

}

The load cell I have came with a table of the manufacturing calibration tests so I would like to replace what's in the OpenScale code currently with the manufacturer's information. They gave the load applied (lbs), load cell output (mV/V), and non-lin. error (% R.O.). I don't know much about writing or altering in any programming language but I assume this is possible.

Any help is appreciated.

Do you have a known accurate voltmeter that will read in the low millivolt range (0 to 50 mV) with 5 microvolt resolution? Do you have known accurate test weights of 5% and 95% of full scale? If not you probably can't do any better than what you have.

outsider:
Do you have a known accurate voltmeter that will read in the low millivolt range (0 to 50 mV) with 5 microvolt resolution?

Yes I believe we have a voltmeter that can read the low millivolt range I'll have to ask one of the electrical students.

outsider:
Do you have known accurate test weights of 5% and 95% of full scale? If not you probably can't do any better than what you have.

I unfortunately do not have weight for the scale because the load cell goes up to 10,000 lbs. I was hoping the the table the company sent would be sufficient.

Thank you.