insert column using ewa (Excel Web Access) via JSOM

I was asked to post the question on this forum.

I have an existing vba code which copies a template from one sheet to another worksheet, and shifting existing data to right.

I just added an excerpt of the code here with super long worksheet names in an effort to avoid back and forth questions :) I am trying to achieve the same using Excel Web Access with javascript.

Dim sourceColumn As Range, targetColumn As Range
Set sourceColumn = Worksheets("WorkSheetContainingTemplateToBeCopied").Columns("C")

Worksheets("TargetSheetWhereTemplateNeedsToBeCopiedAtColumnCWithExisitingDataMovedToRight").Columns("C").Insert Shift:=xlToRight  

Set targetColumn = Worksheets("TargetSheetWhereTemplateNeedsToBeCopiedAtColumnCWithExisitingDataMovedToRight").Columns("C")

sourceColumn.Copy Destination:=targetColumn

I started typing the code, but looking at the api, I felt lost. How do I say insert the data into the targetsheet at column C and move any data existing there.

function CopyRange(SourceSheetName, TargetSheetName) 
{    var ewa = Ewa.EwaControl.getInstances().getItem(0);    var sheets = ewa.getActiveWorkbook().getSheets();    sourceSheet = sheets.getItemByName(SourceSheetName);    targetSheet = sheets.getItemByName(TargetSheetName);    sourceSheet.getRangeA1Async("C:C", getSourceTableRange, null); 
}

function getSourceTableRange(asyncResult) 
{    if (asyncResult.getCode() == 0)     {                     sourceRangeValues = asyncResult.getReturnValue();    }
}