Creating a loop for this working script

Question

I am successfully using this script I found to extract hyperlinks from RTF text:
however I need to copy each file to the desktop and change the file name to do so.
How can I add to the script the ability to
1 - choose a folder
2 - choose a destination folder
3 - loop the script to process all files found in the folder?
I am a new user and I have several students messages all with the same patterns. I will be very grateful to anyone.
Thanks
set filePath to (path to desktop folder as text) & "students.rtf"
set startDelimiter to "{HYPERLINK \""
set endDelimiter to "\"}}"
set linkDelimiter to "Read this message"
set rtfText to read file filePath
set text item delimiters to startDelimiter
set theItems to text items of rtfText
if (count of theItems) is greater than 1 then
   repeat with i from 2 to count of theItems
       set text item delimiters to endDelimiter
       set a to text items of (item i of theItems)
       set theLink to item 1 of a
       set text item delimiters to linkDelimiter
       set b to text items of (item i of theItems)
       set text item delimiters to theLink
       set (item i of theItems) to b as text
   end repeat
end if
set text item delimiters to startDelimiter
set adjustedText to theItems as text
set text item delimiters to ""
writeTo(adjustedText, filePath, false, string)
(*==================== SUBROUTINES ===================*)
on writeTo(this_data, target_file, append_data, mode) -- append_data is true or false, mode is string etc. (no quotes around either)
   try
       set target_file to target_file as text
       if target_file does not contain ":" then set target_file to POSIX file target_file as text
       set the open_target_file to open for access file target_file with write permission
       if append_data is false then set eof of the open_target_file to 0
       write this_data to the open_target_file starting at eof as mode
       close access the open_target_file
       return true
   on error
       try
           close access file open_target_file
       end try
       return false
   end try
end writeTo

Answer 1

etnad wrote:
the script finds the folder
chooses the destination folder
Opens the file for writing
But the result is always false
I am really new to applescript .... maybe there is something missing in the actual writing part of the script?
Thanks
I just tried copy/paste the script, it works well here.
Uses the "on error" in the script, and the history of the editor to know the error.
like this
    on error tError
          log "Error : " & tError
          try
               close access file open_target_file
         end try
         return false
    end try
end writeTo
In the "AppleScript Editor" :
1- click on the tab "Event Log"
2- Run the script
3- Check the text in  "Event Log" to know the error.