Cloning Between Two Graphic Files

I'm brand new to this forum, so I hope you'll be patient with me.  I truly tried to find an answer that might have been previously posted, but I didn't see one...

I'm using PHOTO-PAINT Home & Student X7 version.

I had been trying for a long time to figure out how to clone from one graphic file to another, and I was getting nowhere until I found a nice video on YouTube.  It worked pretty well EXCEPT when I run into the situation of the two graphic files not having the same resolution, zoom level, sampling... whatever it is that determines the difference.  I'll get the two files lined up beside each other; they look fairly compatible in zoom-size, then I go to do the cloning and, OMG!, what looked like a small brush size on the graphic I'm copying FROM turns into a huge brush size when I apply it to the graphic I'm copying TO (or vice versa).  Of course, the amount of pixels being cloned are also greatly changed.  Is this clear as mud?

I have been monkeying around with resampling one of the images, re-zooming because the resampling always throws the graphic to a much smaller or larger resolution.  It just doesn't work, and I'm convinced I'm probably missing some simple solution.  Does anyone know how to synchronize the two files so the cloning will match up?

If you think you might know the answer, but my description isn't sufficient, please ask for more info.  I will be only too happy to supply it.

Oh, by the way, in case it matters - the file format I'm cloning FROM is .cpt (I saved it as PHOTO-PAINT from a .jpg), and the file format I'm cloning TO is .jpg.  Hope this helps.

Thanks for advice.  This has been driving me nuts for a long time.