正規表現じゃないならAppleScript's text item delimitersでできそう。
on replaceText(inText, inOld, inNew) set OriginalDelimiters to AppleScript's text item delimiters set AppleScript's text item delimiters to {inOld} set workData to text items of inText set AppleScript's text item delimiters to {inNew} set workData to workData as string set AppleScript's text item delimiters to OriginalDelimiters return workData end replaceText set theText to my replaceText("名称未設定OSX.txt", "OSX", "OS9")
