Json queries with variables

Hi, I am uncreating this incredible tool and decided to apply an application to the json I would like to try to integrate a variable to the string in this way:

function saveLenguaReg(arg) {
lenBoton2 = arg.data.lenNombre
textoConf1.value = dataIdioma.value.lenBoton2.tslIni01;

But I recivo error I would like to know if this is possible and I would appreciate your help.
(Translated by google sorry)

My json

    	"lenId": "Esp",
	"lenNombre": "idiomaEsp",
	"lenId": "Eng",
	"lenNombre": "idiomaEng",
	"tslIni01": "Hola",

	"tslIni01": "Hello",

This is a Javascript string concatenation question. Use the + operand:

dataIdioma + lenBoton2 + tslIni01

P.S. Please, when you write code in your post, add 4 white spaces at the beginning of the line to format the code as done in the above line.

I really appreciate your time and response
Already try to concatenate the string in many ways including

 TextConf1.value = dataLanguage + lenBoton2 + tslIni01;

Admeas of:

TextConf1.value = dataLanguage.data + "." + LenBoton2 + "." + TslIni01;
TextConf1.value = "datadata.data." + LenBoton2 ".tslIni01";

And I can concatenate the value
I just want to get the result that gives me this string.

TextoConf1.value = dataLanguage.value.language.tslIni01;

This string goes to json and looks for the correct value
I need to be able to change the languageEsp value by lenBoton2 to be able to do a json that when modifying add more languages and no option gave me the result, I would appreciate it if you took a little time to take a look:

Separate in a single file the part with which I have problems I hope it is simpler to get me to understand the idea:

    var Observable = require("FuseJS/Observable");
    var Bundle = require("FuseJS/Bundle");
    var dataIdioma = Observable();
    var textoConf1 = Observable();
    var lenBoton2 = Observable();
    var tslIni01 = Observable();

    Bundle.read("Sjson/jIdiomaGral.json").then(function(leguajetab) {
        var lenguadata = JSON.parse(leguajetab);
        dataIdioma.value = lenguadata;

	function saveLenguaReg(arg) {
	 lenBoton2 = arg.data.lenNombre
	 textoConf1.value = dataIdioma.value.lenBoton2.tslIni01;
    module.exports = {
        tslIni01: tslIni01,
        dataIdioma: dataIdioma,
        textoConf1: textoConf1,
        saveLenguaReg: saveLenguaReg, 
        lenBoton2: lenBoton2
			<Rectangle Dock="Bottom"   Height="70" >
		    	<Text Value="{textoConf1}"/>
		    	<Rectangle Color="#DDDDDD" />
        		<Grid ColumnCount="1">
        			<Each Items="{dataIdioma.idiTIni}">
                    	<Panel  Clicked="{saveLenguaReg}">
	                        <Text Value="{lenNombre}" Margin="20" />
    	                        <Scale Factor=".95" Duration=".08" Easing="QuadraticOut" />

Thank you