One way to do this would be to use External Data on the project page. You would then import a simple text file, csv or something similar, with x, y, z points and then the forces Fx, Fy, Fz. When you load in the data in External Data, you can define the columns as Coordinates and then the others as Forces. The force ones will be give a name like File 1:Force 1, File 1: Force 2, etc. Then you can go into Mechanical (make sure you create a link between the external data and the static structural on the WB page) and then apply this Imported Load on the required face. You can set the interpolation method and even visualize the imported load. You won’t likely want to do a direct nodal force as if you change your mesh then you would have to regenerate the forces all over. A sufficiently fine Interpolation file is more valuable.
I would recommend you do a test case on a simple inclined plate before moving onto your actual geometry. It is easier to understand and debug when you have simple geometry.