If you have an unseeded group, there's several ways. You could put the list of teams in column A, then put =RAND() in column B, copied down, then sort the columns by B.
Converting the existing formulas to handle seeds or non-seeds would be tricky. If you want a similar type formula, try this one:
| A | B | C | D | E | F | G | H | I | J | K | L |
---|
A | Group 1 | Group 2 | Group 3 | Group 4 | Random Draw | | | | | | | |
B | I | A | H | J | Group 1 | K | | | | | | |
C | K | B | L | G | M | | | | | | | |
D | F | M | N | C | D | | | | | | | |
E | O | D | P | E | O | | | | | | | |
F | Group 2 | I | | | | | | | | | | |
G | F | | | | | | | | | | | |
H | C | | | | | | | | | | | |
I | P | | | | | | | | | | | |
J | Group 3 | A | | | | | | | | | | |
K | N | | | | | | | | | | | |
L | G | | | | | | | | | | | |
M | J | | | | | | | | | | | |
N | Group 4 | L | | | | | | | | | | |
O | E | | | | | | | | | | | |
P | B | | | | | | | | | | | |
H | | | | | | | | | | | | |
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If entered correctly, Excel will surround with curly braces {}.
Put the formula in L2, confirm with Control+Shift+Enter, and copy down. The first four cells are Group 1, etc. Like the other formulas, this recalculates every time you push F9.