In practice, it's easy to create that lookup table.

Using that combination generator, generate all possible 4-, 3-, 2-, and 1-letter combinations of a, b, c, and d. You'll get a long list of aaaa, aaab, aaac, etc.

Then, making sure each entry will include a prefix of "=" and a delimiter of "+", generate all possible 4-, 3-, 2-, and 1-number combinations of the numbers 4, 3, 2, and 1 (IN THAT ORDER!!!! THE SAME ORDER AS THE LETTER SCORES!!!!). You'll get a long list of =4+4+4+4, =4+4+4+3, =4+4+4+2, etc.

Then, using some Word magic, create a two column table with all the letter combinations in one column (but with each combination in their own row) and the equations in the other (but likewise with each list element in its own row). Make sure you have the correct equations associated with the appropriate letter combinations. (The Word magic includes highlighting your long lists and under Insert, select Table and "Convert text to table", and other arcane stuff. Good luck.)

Then, paste the whole thing to an Excel cell. Excel does the calculations on the spot and voila, you have a 341-row lookup table.