"I am not quite sure how to perform bit swapping in Excel without resorting to VBA."

I was thinking of using Excel to create the data for the lookup table to do the bit swapping.

I'd go something like this (without actually trying it):

Use Fill/Series to create a column with numbers 0..255 (of course, you don't type 'em all manually!);

Use the DEC2BIN Worksheet Function fill the next column with the binary values 00000000..11111111;

Use string functions to create the bit-reversed values in the next column (I'd probably use a couple of intermediate steps);

Convert back to Hex - giving the required table entry values!

NB: If you select a range of cells, type something in the 1st cell, then press Ctrl+Enter (instead of just Enter), your entry will be "filled" into the whole of the selection in one go!