Help with IR sensor and GND to pins

Hi, I need to make that if the IR sensor detects code 20 then it is dropped on pin 8 GND (only 1, in 10ms) if it detects 21 then it is dropped on 9 and so on. Is there any way to do this ?

It's supposed to serve as a fix instead of a remote control on the home theater. (The whole board is broken and I don't have a plan to fix the crossed path etc.)

On my home theater, I have 6 inputs CENTER + - BASS + - VOL + -
So far I have it wired to GND and the push buttons, the home theater has to drop GND (-) to change the volume, bass, or center settings. I wanted to convert it to an IR sensor, but I have no idea how to make it so that when the button is pressed, it drops into the home theater - (GND) somehow ?

assuming "dropped" mean make low

    if (20 == irCode)
        digitalWrite (8, LOW);
    else if (21 == irCode)
        digitalWrite (9, LOW);

how do the pins get "picked up"?

I tried this, the problem is that when I set pinMode to output, GND is always active, if I don't set it, digitalWrite won't go logically :confused:

how/when do you expect the pin to be driven HIGH (not LOW to ground)?

is the assumption that when another pins is set LOW, all other pins are set HIGH, or is there a code to set a pin HIGH?

I don't understand you at all now, my English is really bad. I don't want to have any PIN HIGH (Except IR sensor) I need to have GND output on pin 6-13 after pressing the button on the controller (Different buttons different code)

I don't know how to achieve this at all... Please try plain English because even translator can't translate it well.

what do you mean by "dropped"? do you mean made LOW (0)?

if so, how does the pin get made "HIGH (1)"?

I don't want to have HIGH pins. And yes, I meant that he became GND

then what is the purpose of the code?
set the pins LOW at startup ... or just connect whatever those pins are used for to ground

I need to get simply GND on pins 6-13, for milliseconds, after pressing the button on the controller. If I always connect it to GND pins 6-13, my home theater will be quieter and louder all the time. (So ​​far, I have solved it via buttons that are connected to GND, and release after pressing the GND button, but this solution does not suit me, and it does not look aesthetically pleasing either)

do then ever need to be HIGH? before pressing the button or when the button is not pressed?

No, I don't need to

i don't understand ?????

I don't need HIGH, I only need GND. If I put HIGH instead of GND in the home theater, it short-circuits

so why use a processor to control these pins if they can only be LOW (ground), otherwise cause a short !!

I do not understand ??