Convert the string to a decimal then divide it by 100 and apply the currency format string:
string.Format("{0:#.00}", Convert.ToDecimal(myMoneyString) / 100);
Edited to remove currency symbol as requested and convert to decimal instead.
Convert the string to a decimal then divide it by 100 and apply the currency format string:
string.Format("{0:#.00}", Convert.ToDecimal(myMoneyString) / 100);
Edited to remove currency symbol as requested and convert to decimal instead.