if they are in columns of excel, read it as a matrix (for a all-numeric matrix),
data = xlsread(filename);
now let's say you have 5 columns with columns 2-4 being the interested thing for you. Then simply,
f = figure;
h = plot(data(:,2:4))
to differentiate lines you can add legends,
legends('line1','line2','line3','last line')
