remove decimal frm ledger and voucher but not from RATE

i want to remove decimal from the ledgers and voucher except the rate..when i changes it from company alter

 

[#Field:RateField]
Format:"Decimal:3"

 

not working

 

when i change the decimal to zero in currency it changes amount and rate to non decimal but i want rate to be in decimal
please help
ii tried a lot to do on my own but nothing works!
please