How can I quickly and easily import matrices from Excel/TXT/CSV formats?

1) By using the AddIn 'Load Matrix From Excel'.
2) By using copy & paste of cell ranges.
3) By reproducing matrix formats by using i.e. a short programm code, i.e. the $O-format:
http://vision-traffic.ptvgroup.com/faq-files/PTV_ReformatMatrix.zip