Averaging multiple cells selectively for numeric and non-numeric scalars

I was wondering if it was possible to average multiple ascii files together selectively based on numeric and non-numeric data found in the file. For instance, some files have the words 'noise' and others 'non-noise' which can not be averaged together. While others start at different values (3000 vs 1) and must also be taken separately. I apologise if my question is to vague and I appreciate any help that can be given. Also, I am having trouble opening the ascii file as a matrix (it opens as a cell) which may be why I am having so many problems