Using eval is an awful way to solve this task. The documentation explains much better (simpler, neater, faster, more robust, more efficient,...) ways to process a sequence of files:
And also this has been explained many times on this forum:
About the worst solution would be to use eval, you might like to first know what the MATLAB documentation says about it: "A frequent use of the eval function is to create sets of variables such as A1, A2, ..., An, but this approach does not use the array processing power of MATLAB and is not recommended."
You might also like to read what experienced MATLAB users say about what you are trying to do (hint: they strongly advise against it):
A much better solution is to load your data into one variable, and then simply access the data using indexing and/or fieldnames, e.g. if you use load then always load into an output variable. This will more efficient, neater, more robust, easier to check, easier to debug, faster,...
PS: Microsoft Notepad is a propriety text editor. I suspect you mean to write "text file", because "notepad files" do not exist.
