typoscript - globalvar for file property

#                             temp.slideshow
#############################################
temp.slideshow = COA
temp.slideshow {
    1 = COA
    1{
        stdWrap.required = 1
        stdWrap.outerWrap.cObject = TEXT
        stdWrap.outerWrap.cObject.value = <img src="{$constant.baseurl}/| " />
        2 = IMG_RESOURCE
        2{
          file{
            import.data = levelmedia:-1, slide
            import.listNum = 0
            treatIdAsReference = 1
            width = 900
            height = 300
            #width.field = imagewidth
            #height.field = imageheight
          }
        }
    }
    2 < .1
    2.2.file.import.listNum = 1
    3 < .1
    3.2.file.import.listNum = 2
    4 < .1
    4.2.file.import.listNum = 3
    5 < .1
    5.2.file.import.listNum = 4
}
#------------------- exception frontpage
[globalVar = TSFE:id = 1]
temp.slideshow.1.2.file{
    width = 900
    height = 450
}
[global]