Getting a package installer to ignore MS installation 'failures' (error dialogue supression) and continue

Hello, I'm a so-so software packager and I use an automated package wrapper built using Winbatch. (Don't ask, I didn't do it.) I have software which has been provided by an unnamed vendor. Prior to the main install it does a pre-check and attempt to install up to four MS-related programs (SQL and VCDistributables C++, both x86 and x64). If you run it without any switches a dialog pops up saying it failed and if you wish to Retry or Skip. No big deal, EXCEPT I want to make this a silent install. Seriously, it doesn't matter if the install 'failed' because the program already exists. However, these dialogs are enough to kill the install when using /S /v/qn switches.

The main installer is a setup.exe which calls to a setup.msi package. Going to the vendor is out of the question, we're on our own.  What's the best way to squelch the failure dialogue? I'm pretty sure this is the cause.