Thanks Ilya for your prompt response. Good news is that it works for 64 bit environment! Unfortunately, this doesn't seem to affect the 32 bit one. Also, I need to hardcode the path to that msi file (which is totally fine actually):
Oh, this is because AppVeyor build works are x64 VMs and 32-bit ODBC driver cannot be installed on it. If you try to install 32-bit ODBC driver manually you will see 'Unsupported operation system' error.
I think that there are some misunderstanding about platform setting in AppVeyor. It is msbuild target, not OS bitness.