Q Light Controller+

Hello all. Maybe this is is as simple as i am overtinking but my problem is the following:
I have a slider that get his value from external midi source that send the vumeter value, so it keeps changing each 100ms, so i can dim the lights at sound volume changes, thats nice and works perfectly.
I want now a button below the slider to STOP the slider from receive the signal and set it to 0 until i click the button again, like if a MUTE button.
Thats the button i dont know how to do it. Its something cannot be accomplished or i am missing something really simple?

Thanks in advance.

As you only tell us that your slider gets ITS value from an External Midi Source, but don't tell us what your slider does, it is difficult to give a specific answer (next time you could attach your workspace, to make it easier for others to understand what you are trying to achieve).

Let's assume that your Slider is set up in Level Mode and that it controls the Level Channel of a Fixture.
Create two scenes for that Level Channel of your Fixture: one with value 255 (call it Full) and one with value 0 (call it Dim).

First option: Change your Slider from Level Mode to Playback mode and select the "Full Scene".
Create a Button underneath it and select the "Dim Scene".

Second Option: Create two buttons in a Solo Frame (for the "Full Scene" and the "Dim Scene").
Now create another Frame and put your solo frame inside that frame (with Cut & Paste).
Next also put your Slider inside that frame and change the mode to Submaster.
(If you read the manual you will find that the Submaster controls everything within a frame, that's why you need that second frame).

Another option would be to put your slider in a Multi Page Frame:
On page 1 you set the External Input, on Page 2 you use the same slider only this time without External Input.