Particle Control

I'm looking at the part from around 0:45 to 0:47 in the linked video. I'm wondering: Is there a way to control the particles to move them only to a certain region? I don't mean confining them to a mask. I mean, is there a way to control the particles almost individually, maybe as clusters, and make them flow to a very specific region in a composition? For example, when using the 3DCamera you can set it to "Use Target" and then set the X, Y, and Z coordinates you want it to center to. So is there a similar way to lock the particles so they flow to that set/selected point or region only or is the only way to use masks and keyframes?

I was looking at some videos about the pcustom node, which gives you a lot of control if you know which formulas to use. Is that the node to use for what I'm asking or are there other nodes?

Blow particles away from a certain region and reverse the result.

Blow particles away from a certain region and reverse the result.

I'm currently doing some tutorials on the pcustom node. Gives a ton of control over particles, the math is just a little insane and something I'll need to study and get good at. Very interesting though, and the possibilities are seemingly endless.