A notice lis pendens is a notice that a lawsuit has been filed which lawsuit could effect title to the property. There is no specific form of a notice lis pendens but it includes the name and case number of the lawsuit and the legal description of the property that could be effected by the lawsuit. It is recorded with the register of deeds in the county where the property is located.
Your question presents a number of potential issues, including the length of time his house has been on your easement. If it has been there for more than 15 years, he may have acquired title or extinguished the easement by adverse possession. You should consult an attorney as soon as possible because the longer you wait you may have more problems enforcing your rights. You should probably file suit as soon as possible and record the notice of is pendens as soon as possible.