[TYPO3] TYPO3SCRIPT Section Menu

[Rocky]

Hey Group,

I'm a newbie in TYPO3 community.I have the following navigation system
##############NAV SYS BEGIN####
PAGE 1
PAGE 2
PAGE 3
PAGE 4 (I give it "not in menu" property. This page and subpages make up 
a special section)
  Subpage 1 of PAGE 4
  Subpage 2 of PAGE 4
  Subpage 3 of PAGE 4
   subpage A of Subpage 3
   subpage B of Subpage 3
#################NAV SYSTEM END###########

I want the special section's navigation bar show only the below items

##########special section nav system begin########

  Subpage 1 of PAGE 4
  Subpage 2 of PAGE 4
  Subpage 3 of PAGE 4
   subpage A of Subpage 3
   subpage B of Subpage 3
############special section nav system end#########

Right now I'm applying an extension template(Give the subpages of PAGE 4 
another look) to PAGE 4. The problem is I do not know what MENU property 
I should use in the section template to get rid of the items from PAGE 1 
to PAGE 3 being shown on navigation bar? Can any of you give me a hint 
please?

Thanks a lot in advance!

Rocky