From the exec documentation:

The exec function executes a system command and never returns.

And when executing the following script

exec "dir /s d:\\temp\\";
print "done\n";
exit 0;
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I get the warning

Statement unlikely to be reached at test6.pl line 2.
        (Maybe you meant system() when you said exec()?)
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So exec isn't likely the correct answer to "getting back control". ;-)