There is no "traditional" access to the calendar data in this manner. BlackBerry does not provide a desktop PIM...rather, it allows you to synchronize with a variety of compatible PIMs (e.g., Outlook), and you would access your data there.
Now, if what you did was backup rather than synchronize, then that backup file (IPD or BBB) is of a proprietary format, with only one native intent -- to be used as the source of restore to a BlackBerry device after catastrophic failure. There are 3rd party PC apps you can search for that can extract the data from the backup file, but I have no idea of the utility afterwards -- you'd need to investigate those to find out (a few seconds searching the Internet for "BBB Reader" or "IPD Reader", depending on which you have, will reveal plenty of candidate apps for you to investigate).
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.