How to use a bash command as a custom shortcut?

I have a command to turn on/off a touchpad (that works in terminal):

param_name=TouchpadOff; touchpadoff_value=$(synclient -l | awk -v param_name=$param_name '$1==param_name {print $(NF)}'); (( tmp_value =  $touchpadoff_value - 1 )); synclient TouchpadOff=${tmp_value#-}

and I'd like to set it as a custom shortcut.

I tried to use sh -c:

sh -c "param_name=TouchpadOff; touchpadoff_value=$(synclient -l | awk -v param_name=$param_name '$1==param_name {print $(NF)}'); (( tmp_value =  $touchpadoff_value - 1 )); synclient TouchpadOff=${tmp_value#-}"

but it still didn't work properly - it was able to only turn on the touchpad.

I was also trying to add quoting marks for variables ("$param_name") but it changed nothing.

Where am I mistaken?
I'd like not to create any script containing the command.

I tried to debug the command, so I created a script containing it, made it executable (chmod +x script.sh) and run debugging mode: sh -x script.sh.

I got:

+ param_name=TouchpadOff
+ synclient -l
+ awk -v param_name=TouchpadOff $1==param_name {print $(NF)}
+ touchpadoff_value=1
+ tmp_value = 1 - 1
mmm: 1: tmp_value: not found
+ synclient TouchpadOff=

and noticed the mathematical expression is a problem here.

So, I replaced it ((( tmp_value = $touchpadoff_value - 1 ))) with let tmp_value=$touchpadoff_value-1.

Unfortunately, let doesn't work with sh and I used bash, and here is my working solution I pasted as the custom shortcut's command:

bash -c "param=TouchpadOff; touchpadoff_value=$(synclient -l | awk -v param_name=$param '$1==param_name {print $(NF)}'); let tmp_value=$touchpadoff_value-1; synclient TouchpadOff=${tmp_value#-}"

You could try to make an alias. Do: man alias to get helping the exact way. They are probably in: /home/[user]/.bashrc There is probably a complex example. An easy one is: alias ll='ls -alF'