non plc valve driver question

Hi guys
I'm going to show my ignorance here...but I'm hoping someone here can help.
I've got a late 80's Toshiba inj molder with a valve drivers (amps) built into the controls. One for pressure and one for flow.
They should send 0-300MA to a proportional valve, but even with the control panel set at 0, it won't go below 50MA. (there's an analog gage on the panel) so the pressure will only go down to 400 PSI or so. I would like it go down to at least 200psi..
I've looked the cards over for a trim pot, without luck.
I'll probably never need full pressure, so I was hoping I could put in a resistor or something between the amp and valve to reduce the current the valve sees.
Would this accomplish my goal?
Thanks guys

I will depend on the valve. Many valves hava a minimum setting you cannot go below.

I would try to do a test with a driver that can go to a lower current (or a power supply with current limit works for this as well) and see if I could control pressure in the range I wanted. If it works then go ahead and design the permanent circuit.

a resistor is a good solution, take a big one as it will be many watts.

Thanks guys
Doug