APPLE SCRIPT HELP! Simple Renaming Script

Question

I dont have any experience with apple script but desperately needed this for a work issue. I basically have tons of files with all the same type of name and need to send the first two numbers in the file to the end of the file as a suffix... so this...
01 alexa_02.mp3
needs to turn into this
01 alexa_02_01.mp3
So the function is take the first two characters from the file name of all the files in the folder and rename them with a suffix. Here is what I have so far.
PLEASE HELP! Im desperate!
[CODE]try
    tell application "Finder" to set the source_folder to (choose folder with prompt "Pick the folder containing the files to rename:") as alias
end try
display dialog "Change Suffix to First Two Characters of File Name:" buttons {"Send The Pids!", "Cancel"}
set the button_pressed to the button returned of the result
set the item_list to list folder source_folder without invisibles
set source_folder to source_folder as string
repeat with i from 1 to number of items in the item_list
    set this_item to item i of the item_list
    set this_item to (source_folder & this_item) as alias
    set this_info to info for this_item
    set the current_name to the name of this_info
    tell application "Finder"
        if the button_pressed is "Send The Pids!" then
            set the filename to the (current_name & the characters 1 thru 2 of current_name) as string
            set orig to quoted form of POSIX path of current_name
            set dest to source_folder & filename
            try
                set y to dest as alias
            on error
                set dest to quoted form of POSIX path of dest
                set command to "mv " & orig & " " & dest
                do shell script command
            end try
        end if
    end tell
end repeat[/CODE]

Answer 1

Made a short script on my own... normally you could do this using the Finder and run a recursive algorythm, but if you just use find to find all files in a folder that ft your criteria and use these links to generate a list of aliases (posix files) it is way faster and acomplished with less code :-)
set myfolder to characters 1 through -2 of (POSIX path of ((choose folder) as alias)) as text
set foundfiles to every paragraph of (do shell script "find " & quoted form of myfolder & " -type f -iname \"*.mp3\"")
repeat with afile in foundfiles
set afile to ((afile as text) as POSIX file as alias)
tell application "Finder"
set filename to name of afile
set filesuffix to (characters -4 through -1 of filename) as text
set addonsuffix to characters 1 through 2 of filename
set filename to (characters 1 through -5 of filename) as text
set newfilename to filename & "_" & addonsuffix & filesuffix
set name of afile to newfilename
end tell
end repeat