Lisp - Altering dimension properties

I'm trying to write a Lisp that will change all of the dimensions
settings in an open drawing. My company used to use arrow heads
(Closed filled) for all their dimensions and would like to switch to
using Architectural tick marks.
The problem is that when we are using a drawing of something we have
created in the past, all of the dimensions have arrows and we have to
manually change all of the dimension's arrows, one by one, to arch
ticks. I know there is a way to do this in Lisp, I just haven't been
able to find it on the web. Any help would be greatly appreciated!

Thank You,
-Brian
AutoCAD 2006

 

Here is the code I have right now:
(command "DIMBLK" "ARCHTICK" "DIMBLK1" "ARCHTICK" "DIMBLK2"
"ARCHTICK")
(sssetfirst nil (ssget "_X" '((0 . "DIMENSION"))))
(command "DIM" "UPDATE" "PREV" "" "EXIT")
This sets the dimstyle for archticks, selects all of the dimensions,
and then updates them. The same problem still exists though, in that
if the existing dimensions have different scales, colors, etc. they are
all modified. I think what I really need to happen is the following
pseudo-code:

-Create a list of every dimension in the drawing
-Create a list of every dimension in the drawing's dimstyle
-Loop for each dimension
-Set the dimstyle of the dimension to the current dimstyle
-Set the DIMBLK, DIMBLK1, and DIMBLK2 variables to "ARCHTICK"
-Update ONLY that one dimension
-End Loop

Is this even possible? Any help would be GREATLY appreciated!!!

Thank You,
Brian W.