'...so, I rename the files to *.asc and then import the data into Excel. (In the options, you only need to change the decimal point to a comma).'
Then the data can be perfectly edited.
Unfortunately, Excel can only handle two y-axes. A better option is Origin Pro 7.5 from OriginLab. It can also handle multiple y-axes and is very easy to use.
...so, I rename the files to *.asc and then import the data into Excel. (In the options, you only need to change the decimal point.)
Change decimal commas)
I do it like this:
-> create (and save) a blank Excel sheet (.xls).
-> In the log file, press Ctrl+A and Ctrl+C (to select all and copy).
-> In the empty .xls file, right-click and select "Paste Special -> Values".