[May the judge, if the claimant does not know how to formulate his claim, order someone to write his claim for him?]

The answer – with success from Allah – is that if the claimant does not know how to formulate a claim, and the judge has understood from his state and his speech that he does in fact have a rightful claim against his opponent, but that he has not been able to express it properly because of his ignorance, or his extreme rusticity, or his speech impediment – then there is no objection to sending him to someone who will look into what he wants and examine what is in his mind, then write out the claim for him accordingly.
Indeed, if the matter is like that, it is not permissible for the judge to nullify his claim and turn away from hearing it, because the responsibility and function of the judge is to repel injustices, and to grant people justice, one from another, and so on; and that cannot be achieved except if he does what we have mentioned. This is not counted as the prohibited prompting (talqīn); for prompting is when the judge says to the claimant: “Say such-and-such, and do not say such-and-such,” or “Deny, and do not confess.”

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2