The BAI-PC is a commercially distributed and ethically controlled test. As such, it will be very difficult to find the actual test on the internet. It is distributed by Pearson Education, Inc. and they may be willing to send you a sample copy or allow you to use it in a research application. The publisher may require you to furnish information regarding your education, research experience, etc before they release the test to you. .
Other uses would require you to purchase the test. Sometimes pharmacy companies like Pfizer or Upjohn or Merch purchase the rights to distribute the test to their docs. You might also be able to obtain a copy through those channels. Here is a short description from the National Center for PTSD and instructions for obtaining the stest..