I need to bake a custom alpha map with transparency

So I am making some ruins but the client wants me to use as many default Roblox textures as I can because they already have a ton of models with default Roblox textures in the game. However, when I imported the ruins and used just the Roblox textures, it looks AWFUL. So I am thinking of adding a transparent kind of alpha map over the top of it but instead of it being black and white, it is green and transparent.

The way I am thinking of doing that is making a procedural green mossy kind of texture and then baking it in a way where the white spots are transparent in the final bake image. However, I am not sure how to do that.

Here is what the moss texture looks like. So the white spots, in the bake, would be transparent.

Here is the node setup I am using.

If you have any suggestions/questions/comments. Please leave them :smiley:

Ok I figured out how to do it a different way but still get the same effect that I looking for.

you make the dirt texture black and white. bake it. save the image. put it in photoshop. do select>color range. then select the shadows preset and play around with the colors. then cut into new layer the selected stuff. export and blah blah blah