using a stick to change thrust and not set thrust

[Teladyex]

I'm using a HOSAS setup and, for my left stick, I tried to set Y-axis - to reduce throttle and Y-axis + to increase throttle and instead of doing that it just treats my stick as a regular throttle.
Is there a way to simply change thrust when moving the stick and let the thrust stay at its value when the stick is in neutral position instead of going to 50%?

[Jukelo]

What you are describing is a relative axis. NO doesn't let you configure an axis as relative, so you'll have to use your joystick's configuration software. If it doesn't allow you to do that, Joystick Gremlin can.