I would like to replicate the behavior of the old creep pop. where I can control the particle motion though custom expressions.I wondering how to do that in new dop pops.

I think there is no direct way to place particle on suraface in POP DOPS.

Tried to use popcollsiondetect and point the SOP path to the particle source geometry and set behavior response to slide.When I applied pop wind with noise,Even then particles are leaving the surface.

Here is my dirty solution!

Tricky but possible, normalized age of the particle drives the position of the particles along UV coordinates. If you want to speed up the motion just multiply the normalized age (inside the voppop after you divide the age by the life) by any number you want or promote the parameter.

Right now there is no way to sticky particles to the surface by collision, I don't know why.

Two surfaces in the file.