I am sorry you are being required to use that HP Product. BSA exports in a xml format, and that is the only method of export. You will have to manually build all of the packages in the HP product.
BSA also works with the native OS/installer product, and then wraps instruction around it. That is the same premise that HP uses as well. BSA just does it far better.
you can use some perl xml modules or similar to process the exported xml files to convert to something that the other tool can use. you would want to extract the install command, the binary location as well as any parameters you need to pass to the installer.