I've a mat file with 24 variables inside and I would like to load only the 100 first value of the variables named Var1 and Var2 in the mat file.
This utility on the File Exchange looks like it may do the job.
Have a look at the
matfile function (should be available from 2011b on). The documentation explains it pretty well.
obj = matfile('test.mat') % save a variable obj.foo = magic(30); % load a variable obj.foo(5:10,3:4)
In previous versions this is unfortunately not possible, see here
Best option would thus be to load in all variables and then create new variables containing only the first 100 values.