Added simple vba example

Examples/VBA/HelloWorldVBA.ps1

@@ -0,0 +1,38 @@
+$xlfile = "$env:temp\test.xlsm"
+Remove-Item $xlfile -ErrorAction SilentlyContinue
+
+$Excel = ConvertFrom-Csv @"
+Region,Item,TotalSold
+West,screwdriver,98
+West,kiwi,19
+North,kiwi,47
+West,screws,48
+West,avocado,52
+East,avocado,40
+South,drill,61
+North,orange,92
+South,drill,29
+South,saw,36
+"@ | Export-Excel $xlfile -PassThru -AutoSize
+
+$wb = $Excel.Workbook
+$sheet = $wb.Worksheets["Sheet1"]
+$wb.CreateVBAProject()
+
+$code = @"
+Public Function HelloWorld() As String
+    HelloWorld = "Hello World"
+End Function
+
+Public Function DoSum() As Integer
+    DoSum = Application.Sum(Range("C:C"))
+End Function
+"@
+
+$module = $wb.VbaProject.Modules.AddModule("PSExcelModule")
+$module.Code = $code
+
+Set-Format -WorkSheet $sheet -Range "h7" -Formula "HelloWorld()" -AutoSize
+Set-Format -WorkSheet $sheet -Range "h8" -Formula "DoSum()" -AutoSize
+
+Close-ExcelPackage $Excel -Show