从注册表更改INSTALLDIR（使用InstallShield）

I'm working with InstallShield and creating an installation that is like an addon. It must read from registry where the program X has been installed and then add the necessary files to the found location. My problem is this : On 32bit computer the registry will be found under HKEYLM\Software\X. On 64bit computer the registry will be found under HKEYLM\Software\Wow6432Node\X.I'm working with InstallShield and creating an