Changing the throttle input sensitivity?

Hello everyone, I was wondering if there is a way to change the rate at which the throttle of your plane increases/decreases if you're using button inputs instead of a throttle lever. I'm using a Logitech Extreme 3d Pro, and on other games I usually have the throttle set to my shift and ctrl keys, but since in DCS they are modifiers I can't do that and instead have to use buttons on my joystick for easy access. I use WASD for looking around and other keys on the keyboard for various systems so using the throttle lever on the joystick isn't an option, since I'd have to move my hand away.

My question is: is there any way to modify the rate at which the throttle increases/decreases when using buttons, or a way to decrease the sensitivity of the input? Maybe in the config files or something?

Thank you in advance.