How to keep directory structure when using nmake install?

[Mozzie]

Hi,
today, when I was using 'nmake install' to install my project , but I found that the header files comes from different directory went to the same target directory.
and my config is:

target.path = $$RELEASE_PATH/lib

header.path = $$RELEASE_PATH/include
header.files += $$HEADERS

INSTALLS += target header

is there any way to let header.files keep its directory structure?
thanks.