Используйте функцию TEXTSCAN :
%# parse file (change the data types if necessary)
fid = fopen('file.dat','rt');
C = textscan(fid, '%d/%d/%d %d %f', 'Delimiter',' ');
fclose(fid);
%# put columns in separate variables
[dt_month,dt_day,dt_year,val1,val2] = deal(C{:});
%# convert to serial date
dt = datenum(double(dt_year),double(dt_month),double(dt_day));