Open the 2 images in Paint Shop Pro. Look at the Image Information for each (Shift+I or from the Image menu) and calculate the width and height required for the finished image. Create a new image with the appropriate canvas size. Click one of the images to select it then press Ctrl+C to copy it. Click your new blank canvas then press Ctrl+L to paste the copied image as a new layer, then reposition that half of the photo on the canvas using the Move tool. If the Move tool isn't visible then click the little arrow at the side of the Pick tool and select it from there. Click the second image then Ctrl+C to copy, click the canvas again and Ctrl+L to paste a second layer and then reposition that also. Once satisfied that they are matched up, you can use "Layers, Merge, Merge All" to combine the images into one.