How to set Stretch Option in VBA

hi

I added a shape and set background use a picture,now i want to set the stretch options,and no tile.

there is  some bug in 2007 I think,for example: if I set tile picture as texture,scale x&y should be 0.8=80%,but some picture i need to set scale 0.008.

so i can only set stretch option to make sure the picture display no problem.

so how to set stretch option in vba?

thanks for your help.