Source
- use an escaped dollar sign twice!
my_custom_target.command = $$QMAKE_MOVE \$\$file \$\$other_file
will result in the shell command mv -f $filw $other_file
(I think the double dollar sign is necessary to escape the first dollar sign in the Makefile, and the backslashes just escape the dollar signs for qmake so that they end up as literal dollar signs in the Makefile)