The following onEditLabel event handler converts all labels to camel-case by converting the string to proper-case and removing all spaces:

function TREEVIEW1_onEditLabel(text)

   local cRet 

   cRet = proper( text ) 

   do while " " $ cRet 

      cRet := stuff( cRet, at( " ", cRet ), 1, "" ) 

   enddo 

return cRet