I looked into this and found it's the same exact file that was released by the manufacturer, but Dell has placed their customizations within the file you are inquiring about.
Here's the link to grab it:
http://drivers.softpedia.com/get/BLUETOOTH/Broadcom/Broadcom-WIDCOMM-Bluetooth-Driver-6516930-for-Vista-Windows-7-64-bit.shtml
Good Luck!