Slideshow: How to add pictures at a defined position

[hsterr]

When I create a new slideshow, I have a problem: I just can add pictures always *at the end* of the pictures already in the slideshow; so I have to click the picture up the other pictures, until it reaches the proper position.

1) Why is it not possible to add a picture at a defined position (for example by marking the picture before the wanted position and then click "add" or something like that)
2) If this is not possible, why not having the "up"-button in permanent function when clicking on it and holding the mouse-button, so I won't have to click twohundred times, when I add a picture to a existing stock of 300 and wanting it to go to position, say, 99.

Thanks for answering,
Hans