I suggest you read the documentation for load. You will find that it doesn't load your text file (or it might by accident). Some relevant functions for loading a text file: fopen, fread, textscan and fclose.
To compare two dates, I would suggest converting your text to a datenum. Also, remember that double quotes will generate a string array, while single quotes produce a char. Both have their use, but in general input for functions should be char. For comparing two chars, you should use strcmp to avoid Matlab trying to compare element-wise, which may result in an error for unequal sized string inputs.
I your goal is an output of an excel file, why bother with a text file intermediary? Just go for xlswrite (which, despite the name, is also capable of writing xlsx files).