Easy one! -- Phone number translator

Question

-- I'm writing a scirpt to translate those pesky alpha-numeric phone numbers into regular numeric phone numbers.
-- I'm still unfamiliar with list manipulation, so I need help with the inner statements.
set thePhoneNumber to "1-800-MY-APPLE"
set thePhoneNumberLIST to the characters of thePhoneNumber
set exceptions to "1234567890()- " -- chars that should be left alone
set phoneDialKeysLIST to {",ABC,DEF,GHI,JKL,MNO,PQRS,TUV,WXYZ"}
set x to 0
repeat with theChar in thePhoneNumberLIST
set x to x + 1
if theChar is not in exceptions then -- Translate every non-exception
-- Here's where I need help
--Pseudo code:
-- replace item x of thePhoneNumberLIST with the number of the item of phoneDialKeysLIST that contains theChar
else
-- do nothing
end if
end repeat
log thePhoneNumberLIST

Answer 1

property number_List : "1234567890()- " -- Valid characters.
property letter_List : {"", "ABC", "DEF", "GHI", "JKL", "MNO", "PQRS", "TUV", "WXYZ"} -- Invalid characters.
set phone_Number to "1-800-MY-APPLE" -- Phone number to test, and if needed - convert.
set phoneNumberItems to the characters of phone_Number -- Create a list of characters.
set newPhoneNumber to ""
repeat with i in phoneNumberItems -- Cycle through phone number.
if (number_List contains i) then
set newPhoneNumber to (newPhoneNumber & i) -- Add a valid character to 'newPhoneNumber'.
else
repeat with j from 1 to (count letter_List) -- Cycle through invalid character list, to determine character position.
-- Append numerical equivalent to end of 'newPhoneNumber'.
if ((item j of letter_List) contains i) then set newPhoneNumber to (newPhoneNumber & j)
end repeat
end if
end repeat
newPhoneNumber -- Translated phone number.
  Mac OS X (10.4.4)