如何在不使用WiX安装文件的情况下运行文件？

I'm trying to call RunDll32 on a DLL to install a private key to the machines key store at install time but I don't want to put the file down on disk. I currently have a custom action calls the RunDll and then deletes the file (after it has been installed obviously). I'm trying to call RunDll32 on a DLL to install