[gmx-users] Itp for a longer molecule out of a shorter one

[Alex]

Dear all,
I have the itp file for a molecule (OH-[PPE]1-[PPO]2-[PPE]1-H   it is a
short surfactant), out of that itp, I am trying to create an itp file for a
longer molecule in the form of OH-[PPE]2-[PPO]16-[PPE]2-H where the PPE and
PPO parts are being repeated 2 and 16 times each. For each extra PPO, 10
atoms, 10 bonds 24 pairs, 19 angles and 4 dihedral entries would be added
to the itp file. Doing that for a longer molecule is so tedious, so, I
wonder if anybody has already a script or tools for doing that?
I would be really appreciated.
Regards,
Alex