Does the vendor provide documentation for the silent install of this? Can you provide links to any relevant documentation?
Is the setup file available for download publicly? Can you provide a link to the installer?
What format is the setup installer? InstallShield? NSIS? InnoSetup? MSI?
Look for others online that are able to silently install this software and how they are doing so.
Once you can silently install something, then it is usually fairly easy to adapt that method to BigFix.