need to launch an exe outside the INSTALLDIR

[zathras]

Ciao,
here is the requirement:
ask the user for a directory and launch a file in that directory
returning the version of the software installed in that very
directory.
I managed all of the subtasks coming to mind when receiving this
requirement but one:
when launching the custom action with that executable it
does not seem to find it:
SOURCE: TARGET_SPECIFIED_BY_USER
TARGET: exefile.exe

I managed to get the job done (with a dirty hack) anyway, by
specifying:
SOURCE SystemFolder
TARGET cmd.exe [TARGET_SPECIFIED_BY_USER]\exefile.exe

Any reason why the "launch an executable" - action does not seem to
use
the directory specified in the SOURCE-section of the
action-specification?
(Hint: I could not even launch an exe in the root-directory, it just
launches executables found in the system-path (the SOURCE SystemFolder
line is not really used, I could also use SOURCE fooFolder or the like
to gain the same result))