How to manage X mouse button control simulated “hold” keystrokes?

I have made my right click into the button f , but it only does f once when I click. I want it to act the same, so that I can also hold right click to act as hold f . If that was hard to understand, sorry, but to make it simple: The f key is a button in a game that acts as a parry when I click it and as a block when I hold it. I can only parry with my right click and it does not block when I hold.

Question by Storm Lilleng on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.