Display barcode: Can I use GuiXT to display the barcode for the material number in transaction MM03?

Yes; in fact one script line is sufficient:

Image (1,98)


Explanation: you display an image via a URL. The URL calls up a webservice that returns the barcode for the given material number. There are several web services that return a barcode; for the above example we have chosen www.barcode.tec-it.com