Data folder should never be added to the search path. It's dangerous (you may change what functions are in scope) and there's no need to anyway.
All matlab IO functions accept full paths of data file for import/export. It's much better to specify the full path of files. That way they can be anywhere you want, even on a network folder.
So, instead of something like:
%code that relies on the folder where mydatafile.txt resides to be on the path or be the current folder
data = csvread('mydatafile.txt'); %actual function used for importing is irrelevant
use
%code that works regardless of location of folder. Doesn't need to be on the path or be the current folder
folder = 'C:\somewhere\somefolder'; %location of mydatafile.txt. Could even be remote
data = csvread(fullfile(folder, 'mydatafile.txt'));
