The Transparent property specifies whether a bitmap has no background - that is, has a transparent background - when exported. You can use this property only with formats that support transparency (such as CPT, PSD, and TIFF). This property cannot be used with any other filters, including GIF and PNG. (For the GIF or PNG filter, you can use the filter's interface to specify a transparent color.)
Examples:
The following VBA example exports the selected objects to the CorelDRAW (CPT) format without a background.
Sub Test()
Dim opt As New StructExportOptions
Dim flt As ExportFilter
opt.ImageType = cdrRGBColorImage
opt.Transparent = True
Set flt = ActiveDocument.ExportEx("C:\Temp\img.cpt", cdrCPT10, cdrSelection, opt)
flt.Finish
End Sub