transpose columns in region

Friday, 7 November 2003

        Hello

I would like to transpose columns in matrix like construct like this

1 2        2 1
1 2 -->    2 1
1 2        2 1

I can do this by hand via kill and yank rectangle, but does anybody
know about a package which does this. I searched in the web without
success

Thanks

Uwe Brauer 