OK, I got most of it working. The only thing left is the border. I took this directly from the example in the help file:
xTaskbartopborder 4
xTaskbarbottomborder 4
xTaskbarLeftBorder 4
xTaskbarRightBorder 4
but it seems to be ignoring the left border and putting the icon off center.

the whole thing as I have it set is:
xTaskbarButtonPaintingMode ".image"
xTaskbarX 610
xTaskbarY 0
xTaskbartopborder 4
xTaskbarbottomborder 4
xTaskbarLeftBorder 4
xTaskbarRightBorder 4
xTaskbarButtonMaxHeight 24
xTaskbarButtonMaxWidth 24
xTaskbarButtonMinHeight 24
xTaskbarButtonMinWidth 24
xTaskbarButtonXSpacing 2
xTaskbarButtonYSpacing 0
xTaskbarAutoSize 670
xTaskbarLayout ".horizontal"
xTaskbarButtonDirection ".right"
xTaskbarButtonWrapDirection ".bottom"

xTaskbarWrapCount 25
xTaskbarIconSize 16
xTaskbarAlwaysOnTop True
xTaskbarTrueTransparency true
xTaskbarWidth 0
xTaskbarHeight 24

xTaskbarUseBigIcon False
xTaskbarShowIcon True
xTaskbarShowText False

xTaskbarShowHoverState False
xTaskbarShowPressedState True
xTaskbarImageWidth 24
xTaskbarImageHeight 24
xTaskbarNormalButtonImage stask.bmp
xTaskbarActiveButtonImage stask-sel.bmp
xTaskbarMinimizedButtonImage stask-min.bmp

and the icon seems to be centered vertically, not in a corner, but it refuses to center horizontally.