loadcell amplifier 4-20mA signal output

hi there..
how are u.
hope u all in fine...
i have 400t loadcell. the signal output already converted from mV to mA..
now the initial reading less than 4mA...
question is i need to gain up the 4-20mA signal, that easy to me for calibrating the loadcell..

any suggestion or ideal to do that...

thanks buddy..