I have WordSearch 12 and have purchased The Preacher's Outline & Sermon Bible installed.
Is there any way to convert that file so I can use in eSword?
No there is no way to convert it to e-Sword format and in order for an e-Sword module to be created the publisher, Leadership Ministries Worldwide, would have to grant permission as there is a copyright involved
Not only that, it also comes down to what database system was used to create that resource that makes the resource extremely difficult if no impossible to convert. And even if the same database system was used, other factors could make conversion difficult or impossible.