1) Select cells with pretty expressions within the Mathematica Notebook and click Cell > Convert to > InputForm
2) Cut and paste the resulting inputform code into a textfile, e.g. script.m.
3) Repeat 1)-2) as needed.
4) Terminate textfile with: Exit[]
5) Execute script from the command line prompt with:
~$ MathKernel -noprompt -run “<<script.m”