[Techtalk] A (Difficult?) Regular Expression Construction Question

[Elizabeth Barham]

Dear Ladies and Gentlemen,

   I am trying to fathom a proper method within the constraints of
regular-expressions of dealing with a rather complicated
text-structure. For example,

TECHNOLOGY
Internet, p. 20
Routers, p. 35
Techgear
Apple's New Ipod, p. 21
Compaq's new Ipaq, p. 12
Some new PDA, p. 22
Weatherquest's New PDA, p. 25
UNIX, p. 30

Basically, this is a title (TECHNOLOGY), a series of entries
(e.g. Internet, p. 20), a sub-topic (Techgear) and its own entries -
note where its entries end, however: UNIX, which ends the
forward-flowing alphabetic entry. e.g.:

TECHNOLOGY (title)
  Internet, p. 20 (entry)
  Routers, p. 35
   Techgear (subtopic)
     Apple's New Ipod, p. 21 (subtopic entry)
     Compaq's new Ipaq, p. 12
     Some new PDA, p. 22
     Weatherquest's New PDA, p. 25
  UNIX, p. 30 (entry)

I'm trying to come up with a regular expression that would correctly
identify the "Techgear" and its subsequent entries by noting that the
next-entry (UNIX) is *behind* the last of its own entries
(Weatherquest), but I cannot think of a regular-expression that can do
such a thing, which is a bit surprising because it seems like
regular-expressions can do so much.

Any ideas on how to deal with it with regular-expressions?

Sincerely,
Elizabeth