In simple terms, say you wanted “CHAR” to stand screen right and move to screen left at the same time an overlay moved. You’d have a pre-moving spot (screen right), and a final destination (screen left). In your example, it appears those are the same. If CARMELLA is offscreen at spot 1.28 241 -10, you’ll want to spot her to walk on screen somewhere in 3 seconds (in other words, just change the x coordinate—the second number).
If she’s onscreen at spot 1.28 241 -10, you’ll want to change the x coordinate (second number) to have CARMELLA offscreen.