save the file as a .PNG and import it into flash
If this doesnt work, you should just import to flash, use "Trace Bitmap" on the bitmap and it will be converted into vector graphics. Delete the black area
For better frame rate and file size performance do the following:
-Drag the black area away from the sprites that have been traced.
-Delete the sprites that are left.
-Place the bitmap again into the workspace (import from the library)
-select the bitmap and press CTRL+B 1 or 2 times (depends on your version of flash) you might have to resize the rectangle if it doesnt show the whole bitmap.
-Drag the black area you had before over the bitmap again, in such a way that it matches the silouhette of the sprites
-Deselect and select the black area
-Delete it and youre done.
I hope this helps