反則技ですが、VBScriptを実行する、自前エクステンションを作りました。
テスト
GraphicsWindow.BackgroundColor = "skyblue"
button = Controls.AddButton("caption", 380, 10)
Controls.SetButtonCaption(button, "run")
mtextbox = Controls.AddMultiLineTextBox(10, 40)
Controls.SetSize(mtextbox, 400, 400)
Controls.ButtonClicked = output
WC = Text.GetCharacter(34)
CRLF = Text.GetCharacter(13) + Text.GetCharacter(10)
code = ""
code = code + "Function setup(a)" + CRLF
code = code + " Msgbox(a)" + CRLF
code = code + " setup = " + WC + "a * a" + WC + CRLF
code = code + "End Function" + CRLF
Controls.SetTextBoxText(mtextbox, code)
Sub output
text = Controls.GetTextBoxText(mtextbox)
a = Class1.VBSrun(text)
GraphicsWindow.ShowMessage(a, "vbs")
EndSub