While I'm still not successful to expand $${LITERAL_DOLLAR}0 to the command line at compile, I did resolve the generated compile error by changing from awk to sed.

[Work around]

Change...

myrcupdate.commands = awk \'NR==2 {$${LITERAL_DOLLAR}0=\"$${MY_DIR}\"} 1\' myrc.sample > .myrc

to...

myrcupdate.commands = sed -i \'\' \'2s%.*%$${MY_DIR}%\' .myrc