Initializing the installation folder

[davidang]

Using Basic MSI i want to install a product in a specified directory.

The diroctory is already set in an environment variable (lets say:
MYOLDDIR_VAR) on the target machine.

MYOLDDIR_VAR=C:\myproduct2005

How to determine the value of this variable and how to initialize the destination folder (INSTALLDIR/TARGETDIR) with it?

Thanks in Advance

[RobertDickau]

You might look at set-directory custom actions (to set INSTALLDIR), and at the Formatted data type, which supports the syntax [%VAR_NAME] to expand the value of an environment variable...