Control Radio Panel via Keyboard - Aerosoft A320

Hello.

I want to control the radio panel of my Aerosoft A320 with my keyboard. I know that LINDA does not support keyboard inputs but I noticed that Linda developers have a lot of knowledge about LUA scripts which then can be used with FSUIPC for example.

Is there an availlable script to do that?

If not, how can I get this code to work?
I think I need something like a DspShow (x,y) function. I have seen it many times but can not find any documentation on it.

This is my code so far:

function com1_freq_swap ()
	local temp
	local LVarSet
	local LVarRead

	temp = ipc.readVar("L:Com1Freq")

	LVarSet = "L:Com1Freq"
	LVarRead = ipc.readVar("L:Com1StbyFreq");
	ipc.writeVar(LVarSet, LVarRead);

	LVarSet= "L:Com1StbyFreq"
	ipc.writeVar(LVarSet, temp)
end

function com1_freq_incr_1000 ()
	local LVarVal

	LVarVal = ipc.readVar("L:Com1StbyFreq")
	LVarVal = LVarVal+1000
	
	if LVarVal > 136975 then 
		LVarVal=LVarVal-18000
	end

	ipc.writeVar("L:Com1StbyFreq", LVarVal)
end

The first function should swap the Standby Freq with the Active Freq. But when I execute this function via FSUIPC nothing happens.

The second function should increase the Standby Frequency by 1 Mhz, for example from 119.000 Mhz to 120.000 Mhz. If this works, it should be easy to create a decrease function. 

As far as I know, there are two LVars for the Airbus A320. One called "L:Com1StbyFreq" which stores the respective frequency in the format "120000" and the second called "L:Com1StbyFreq_h" which uses the format "120.000".

Thank you very much for your help.