Hard to get around with some renaming, but it can be minimized if you have many files with same structure (same amount of fields in same order).
Say you have the first load:
FROM [file1] (ooxml, embedded labels, table is Sheet1) ;
For the next loads you can change to refer to generic column headings and rename, by setting to no labels and header is 1 lines (to ignore the labels):
A As Field1,
B As Field2,
C As Field3
FROM [file2] (ooxml, no labels, header is 1 lines, table is Sheet1)
As you see, some renaming needed, but it follows a pattern and can be used in the methods of looping through many files like in the threads that qlikviewwizard linked to. Again, it does require that all files have the "same" columns (but with different names) and in same order. If that's not the case, it gets more complicated.