Thanks for all your help so far, really appreciated.

I need to clarify a little.....

There are many iterations (hundreds) of points and levels that I need to write to another file, and they are all different, for example;

points: "{lbzAb{pnCedn@_t{S",
levels: "PP",

points: "abetBivqgFwtcOv `Ayspb@lhiVopoFxzmEysmBl|s@gv`Bd`M",
levels: "POMMLP",

I need a way of copying the lines containing the values for points and levels (however long the strings are) to the new file. I am now thinking that the substitution operator is not the right one.

My output is therefore the same as the input, in that the script searches the input file for all iterations of:

points: "variable_length_string_containing_any_characters",
levels: "variable_length_string_containing_any_characters",
And simply writes this to another file..Do I need a loop to achieve this?