Here is quick version; this works by using the XPression sequencers currently focused item. It takes the currently focused item and advances; it currently only works with the Take Item group that the focused item is within
'define vars
dim basetakeitem, nexttakeitem, nextfocus as xpbasetakeitem
dim takeitem as xptakeitem
dim takegroup as xptakeitemgroup
'Get currently focused item in sequencer list
engine.sequencer.GetFocusedTakeItem(basetakeitem)
'Take currently focused item
basetakeitem.execute
'Advance sequencer
takeitem = ctype(basetakeitem, xptakeitem)
takeitem.GetGroup(takegroup)
takegroup.getnexttakeitem(takeitem, nexttakeitem)
nexttakeitem.setfocus
#XPression