Use 3d model as base object of particle system?

Hi, I’m trying to use a simple 3d model (with a cube-mesh & material of effect “bultin-standard”) as basic object to be emitted in particleSystem

My approach was to set “Render>RenderMode” to “Mesh” and fill the “Mesh” & “CPU Material” as I wanted

image

The problem is the material won’t let me replace it if new material doesn’t use effect as “particle/butin-particle”
So I copied the internal material named “particle-add” to a new folder & configure it to use the texture as I wanted & the Technique to “Alpha-blend” to show clear texture

Everything seems pretty well except the fact my mesh is not well uv-mapped with the texture, something like this:

image

So I’m stuck and don’t know what to do more to achieve my goal
Anyone please let me know the solution or if there is any other simpler way to do this?
Thanks so much!