I using X code 4.

And Making an US Currency Calculator.

My Aim is to display the numbers in proper format?

Like

$ 1,234

$12,100

$1,23,123

I dont want do this by appending , and string stuff.

Is there any easier way so that I can integrate any RE or 
any ruby or Python. Which will help me to make currency format.

Please show me easier way rather than long programming.