Like Adam mentioned if you don't need to interact with the current-selection-box and want just to display the current selections you could use a textbox with getcurrentselections() for it which is appropriate adhusted. Otherwise you need to build your own current-selections-objects - here you will find some interesting ideas for it: Current Selection Alternatives.
If you are using the desktop client or the IE plugin you could also use a macro - triggerred by (De)ActivateSheet - which changed the IsHidden property of the field to true respectively false. Here an example from the APIGuide.qvw how this property could be read:
set flddescs = ActiveDocument.GetFieldDescriptions
for i = 0 to flddescs.Count - 1
fdesc = flddescs(i)
if fdesc.IsHidden then
msgbox(fdesc.Name & " is hidden")
msgbox(fdesc.Name & " is not hidden")