Difficulty with transparent layers in PSP 7.04

[Syncopator]

I want to apply the same image with a transparent background to a series of different background images.

I can produce an image with a transparent backgound to use as the layer, but after copying it, the options I have when I go to add it to another (background) image, are Paste as New Image, Past as New Layer, Paste as New Selection or Paste as Transparent Selection.

The first three automatically place the layer correctly aligned within the host image's border, but doing so removes the layer's transparency.

The only one which places the layer complete with its transparency is the latter, but it is up to me to place it exactly within the borders of the host image.
As the series of final images will be frames in an animation, the inevitable inaccuracy in pasting the transparent layer correctly aligned every time is unacceptable.

I'm sure that I have done what I want to do before (a simple Paste) but I don't remember how.