[EHaskins]

First you need to be in L2 or PRO mode. On the toolbar at the top of the window you should see L1, L2, and PRO. Select the one you need.

Create a new competition project.

Open the Operator control function.

Under the RC Control section of the commands you should see a "Arcade - 4 Motor". Add this to the Operator control function.

The options for this command are fairly simple.

EDIT: "Advanced" code i attached is fairly simple.

int LeftDrive, RightDrive;
unsigned char JoyY, JoyX;

JoyX = GetOIAinput(1,1);
JoyY = GetOIAinput(1,2);

LeftDrive = Limit(JoyX - JoyY + 127);
RightDrive = Limit(JoyX + JoyY -127);

// the mixing code above  produce values out of the 0-255 range.
// we must limit the values or we will get overloads and weird things.
LeftDrive = Limit(LeftDrive,0,255);
RightDrive = Limit(RightDrive,0,255);

//Assign motor values.
//Left motors
SetPWM(1, LeftDrive);
SetPWM(2, LeftDrive);

//Right motors
SetPWM(3, RightDrive);
SetPWM(4, RightDrive);

The limit function used above.

 
int Limit (int input, int min, int max)
{
  if (input < min)
  {
    input = min;
  }
  if (input > max)
  {
    input = max;
  }
  return input;
}

I have attached a program for you to look at.
If you need more help PM or e-mail me.

EDIT: I have attached another file with custom arcade software. It may be easier to use your "Magic calcs" with this.