I feed a textbox a string value showing me a balance that need to be formatted like this:
###,###,###,##0.00
I could use the value.ToString
This simple solution works for me with US currency.
If not needing international currency support use this and replace the $ with the currency symbol(s) to be removed:
// for USD
string result = currentBalance.ToString("C").Replace("$", "")
or
// for EUR
string result = currentBalance.ToString("C").Replace("€", "")