Setting the installation path with a command line option

Question

I have created a .net dll which must be installed with a setup (named "first setup"). I created the setup and it works fine. I'm getting a few dialogs and one of the dialogs is for the "installation path". The default is the application path.
Now I'm calling the first setup from a second setup in which I have set an installation path, for instance "d:\appl".
The second setup installs my main application in this folder (d:\appl) and the then calls the first setup. I want the .dll to be installed in the folder I have set second setup (d:\appl), and I want the setup to go quit.
To go quit I can set /qb (no dialogs and a progress box), but the dll is placed in the application folder of the second setup.
My question: Is it possible to set the installation path with a command line param?
Somthing like setup.exe /qb /path="d:\appl".