that means format a 1234.567 will get 234.58.
Why would you ever want to do that? Now you users don't know if you are displaying 234 or 1234 of 1000234. Your trouble might be coming from this unusual formatting you are attempting. Most number formatting functions won't do this because it does not make sense. They focus on truncation and rounding of the decimals which simply reduce the LSB's, not the MSB's.
If you must do this, just write your own function to truncate the higher magnitude values.