One solution would be to draw your loaded image on to a bitmap at the desired location, then assign that bitmap to the picturebox. Something like this:

Code:
Dim bm As New Bitmap("c:\mypic.bmp")
Dim bm2 As New Bitmap(picturebox1.width, picturebox1.height)
Dim g As Graphics = Graphics.FromImage(bm)
g.DrawImage(bm2, X, Y)
picturebox1.image = bm2
Don't take that code too literally, but it should be something along those lines. If you Google Graphics.FromImage you should get lots of good stuff.