S7-300 DB Pointer help

I'm a beginner with STL for the S7-300, and am trying to grasp some concepts with pointers for the first time. I'm trying to learn from Berger's STL book, but it's pretty rough.

Right now I'm attempting to create a pointer to a word within a DB. I'd like to be able to specify which word using an Int. From the reading it seems like I'm looking to use a DB Pointer to accomplish this. The book gives one single example on how to create a DB pointer:

P#DB10.DBX20.5

However, directly underneath this example (p413) it states, "You cannot load this pointer". Unfortunately this is exactly what it seems like I want to do. That is, I'd like to load the value from some word in the data block into the accumulator, for instance:

L P#DB_In.Word_Number

Whre DB_In is the DB and Word_Number is the word in the datablock I'd like to have the pointer to. I know this syntax is wrong, but if someone could give me a hand forming the correct syntax I'd be very greatful.

Thank you,
NWT

All accesses to DB's require the DB to be opened first. You can use an Area pointer to access an address that is computed at run time. Area pointers specify down to a bit address, so to address a byte you multiply by 8 (or shift left 3), to address a word you multiply by 16 (or shift left 4) and to address a doudle word or real you multiply by 32 or shift left 5)

e.g.
L 10
T Word_Number
OPN DB 1
LAR1 P#DBX0.0
L Word_Number
SLD 4
+AR1
L W[AR1,P#0.0]

This is the equivalant of
L DB1.DBW[Word_Number]