Thanks a lot Jerimiah,
this is working for me!
However, like you said i need to blank quite a number of datapoints. It's a pity I can't select a number of points at once in the data spreadsheat, or is there a way ?
Also i didn't quite understand how to set up the blank-variable prior to loading it into tecplot. Could you comment that? Since my .plt has >100mb it will be a pain loading it into matlab first i assume.