Hi, probably start by reading in the text file
filename='textfile.txt';
f=fopen(filename);
line1=fgetl(f);
Then you could check each line with a regexp and save it if it does not contain your characters.
if isempty(regexp(line1,'[:=]'))
...% save your line
end
and build a new text file from there.
Hope this helps as a start at least.
