hello!

I think this is called cross tabulation:

in a text line this:
[anything but tab][tab][anything but tab][tab][anything but tab]
[anything but tab][tab][anything but tab][tab][anything but tab]
[anything but tab][tab][anything but tab][tab][anything but tab]
[anything but tab][tab][anything but tab][tab][anything but tab]
etc

all the lines that start with the same:
[anything but tab][tab][anything but tab][tab]
I want to delete them and leave only the first occurence, and at the end of it, append all the last [anything but tab] of each of the deleted lines, seperated by -

how can I do this?

thanks!