Can't you do this by altering the maps script? From memory you guys have the scripts in b_mapscriptdirectory "etpromapscripts" folder.
// accum 0, track state
// accum 1
// - bit 0: barrier1 state ( 0 = not built, 1 = built )
// - bit 1: barrier2 state ( 0 = not built, 1 = built )
// - bit 2: spline status ( 0 = not moving, 1 = moving )
// - bit 3: stuck check flag ( 0 = not stuck, 1 = stuck )
// - bit 4: flag for message ( 0 = dont display, 1= display )
// - bit 5: blank ( )
// - bit 6: temp register (XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX)
// - bit 7: death status ( 0 = alive, 1 = dead )
// - bit 8: player check ( 0 = players, 1 = no players )
// - bit 9: visible state ( 0 = alive, 1 = dead )
// accum 2, blank
// accum 3, current movement loop position
// accum 4, stop counter
// accum 5, lockout ref counter
// accum 6, blank
// accum 7, blank
Around that area :)