You're not being a bother......... that what this section is for. 
I don't have one set up that way on my drive. The only one I have with end caps, uses 4 images. Top, bottom, (verticle) and Right, Left (horizontal)
It's set up like this ................... of course your margins will probably be different.
Name =*_*_*
[Background]
Image = *_*_*Bottom.png
LeftWidth = 16
TopHeight = 16
RightWidth = 16
BottomHeight = 16
[BackgroundLeft]
Image = *_*_*Left.png
LeftWidth = 16
TopHeight = 16
RightWidth = 16
BottomHeight = 16
[BackgroundRight]
Image = *_*_*Right.png
LeftWidth = 16
TopHeight = 16
RightWidth = 16
BottomHeight = 16
[BackgroundTop]
Image = *_*_*Top.png
LeftWidth = 16
TopHeight = 16
RightWidth = 16
BottomHeight = 16