If you wanted to break your original list of names into 4 groups, using 4
columns, say A1 to D5,
with your list of names say in Z1 to Z20, enter this formula in Y1 and copy
down to Y20:
=RAND()
THEN, enter this formula in A1, and drag across to D1,
Then down to D5:
=INDEX($Z$1:$Z$20,RANK(INDEX($Y$1:$Y$20,(4*ROWS($1:1))-4+COLUMNS($A:A)),$Y$1:$Y$20))
NOW, each time you hit <F9>, you'll get a new random grouping list.