Do you want to change it in an existing replay? If there are collisions between Tori and Uke, they will get back to the default distance that the replay was created with.
You need to apply changes to this line:
NEWGAME 0;720 10 0 0 0 2 engagedistancevalue 0 0 classic 0 0 100 0 0 0 1 0 2 0 0 0 0 0 0 0.000000 0.000000 -9.820000 0 0