Both formulas presented above will work.

Ron's:
=LOOKUP(10^99,1/(ABS(AI2:AI102)=MAX(INDEX(ABS(AI2:AI102),0))),AI2:AI102)

mewingkitty's:
=INDEX(AI2:AI102,MATCH(MAX(ABS(AI2:AI102)),ABS(AI2:AI102),0))

Your file posted above is correct, just select the cell, go into edit mode (hit F2), then hold down CTRL and SHIFT while hitting ENTER.

Jason