Hi,
Please tell your vendor or client or source where from you got this file, suggest them to save as this file in lower version (Indesign C4 or later (IDML)). This option you will found when they save as the file.
The process is:
File Menu => Save as => select Indesign C4 or later (IDML) option from format which will appear on below save as dialogue box.
After that you can easily open this file in CS4 version.
Screenshot:
