Planar UV above another texture.

[Anonymous]

Hey guys I am trying to project a planar UV with a logo I have made and saved as png.
On the object there's already another texture and I would like to mantain it below the drawing. I also would like play with the blend mode like in photoshop.

I post some pictures to explain myself better.

The first image is my model, with the textures which is not a planar projection, it's a standard uv mapping.

The second image is the shoe with a planar uv (this time jpg because otherwise the area outside the logo would have been invisible), I have selected some faces, applied the material and then made the planar uv. As you can see in the second img there are no seam on the shoe and on the swoosh.
I need to be able to project the planar on the shoe ABOVE the shoe texture with seams.

How would you do something like this?

Thank you very much in advance to everyone who will help me.