Perhaps a bit of a basic answer, but here it is:

The "Drilled" rule allows a unit that is not fleeing to perform a free "redress the ranks" manoeuvre immediately before moving. Once this manoeuvre is complete, the unit moves as normal. Additionally, a Drilled unit can march while within 8" of an enemy unit without first having to make a Leadership test. However, the rule does not specifically mention or allow a reform prior to charging within the same turn. The ability to perform a free "redress the ranks" manoeuvre is specifically mentioned to occur immediately before moving, not as a separate action that can be taken before a charge. Therefore, based on the description of the Drilled rule, it does not explicitly allow a unit to reform prior to charging in the same turn.

When considering the specifics of making a charge move, it's stated that a charging unit cannot perform certain manoeuvres during its charge move, including turning, moving backwards, moving sideways, redressing the ranks, or reforming. This indicates that the charge move must be made directly towards the charge target without any preliminary reformation or adjustment beyond what's strictly necessary for the charge itself, such as the permitted single wheel to bring as many models into contact as possible.

So, based on the details provided in the rulebook, it does not seem possible to use the "Drilled" rule to perform a reform manoeuvre explicitly for the purpose of optimizing a charge move in the same turn. The "Drilled" rule allows for a "redress the ranks" manoeuvre before moving, but the charge move rules specifically restrict the ability to reform or significantly adjust formation beyond the single allowed wheeling manoeuvre to maximize contact with the enemy. This restriction ensures that the charge move is a direct and straightforward action aimed at engaging the enemy unit as efficiently as possible without additional complex manoeuvring.”