No, you can’t.
Both 16-bit and 32-bit Windows lived in a 32-bit linear address space. The terms 16 and 32 refer to the size of the offset relative to the selector.
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First, notice that a full-sized 16-bit pointer and a 32-bit flat pointer are the same size. The value 0x0123:0x467 requires 32 bits, and wow, so too does a 32-bit pointer. This means that data structures containing pointers do not change size between their 16-bit and 32-bit counterparts. A very handy coincidence.
Neither of these two observations holds true for 32-bit to 64-bit thunking. The size of the pointer has changed, which means that converting a 32-bit structure to a 64-bit structure and vice versa changes the size of the structure. And the 64-bit address space is four billion times larger than the 32-bit address space. If there is some memory in the 64-bit address space at offset 0x000006fb`01234567, 32-bit code will be unable to access it. It’s not like you can build a temporary address window, because 32-bit flat code doesn’t know about these temporary address windows; they abandoned selectors, remember?
http://blogs.msdn.com/oldnewthing/archive/2008/10/20/9006720.aspx