Dynamic variables

Is it possible to dynamically create variables in AS? I tried the script below but it didn’t work.

property AAlastUpdate : " " property ALlastUpdate : " " property ARlastUpdate : " " property DRlastUpdate : " "
set theMagFolders to {"AA", "AL", "AR", "DR"}
tell application "Finder"
set thePath to the folder "merion_image_archive" of folder "Cumulus_Test"
repeat with magName in theMagFolders
set (magName & "modDate") to modification date of the folder magName of thePath
if (magName & "modDate") != (magName & "lastUpdate") then
display dialog (magName & "modDate") & return & "There have been changes to the folder" & magName
--do cumulus scripting stuff here
set (magName & "lastUpdate") to (magName & "modDate")
display dialog "There have been no changes to the folder " & magName
end if
end repeat
end tell