Convert STL/OBJ to STEP file 3d model

I have an existing part saved only as an STL mesh and I need it converted into a clean, watertight solid that I can use directly in engineering analysis software (ANSYS, SolidWorks Simulation, Abaqus, etc.)... (Budget: ₹1500 - ₹12500 INR, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Printing, CAD / SolidWorks, CAD/CAM, Mechanical Engineering, Solidworks)