NumberFormatInfo nfi = new CultureInfo( "en-US", false ).NumberFormat;        
nfi.CurrencyPositivePattern = 0;
string.Format(nfi, "{0:C}", 112.236677); //$112.24 - default
nfi.CurrencyPositivePattern = 1;
string.Format(nfi, "{0:C}", 112.236677); //112.24$
nfi.CurrencyPositivePattern = 2;
string.Format(nfi, "{0:C}", 112.236677); //$ 112.24
nfi.CurrencyPositivePattern = 3; 
string.Format(nfi, "{0:C}", 112.236677); //112.24 $