try doing something like this:
Code:
_asm	
	{		wait
			fnstcw	old_cw
			wait
			mov	ax, word ptr old_cw
			or	ah, 0xc
			mov	word ptr new_cw,ax
			fldcw	new_cw
	}
that exact code is used in some source i have and i know it will compile in msvc++("_asm" is a reserved word). obviously you would want to replace the code inside with whatever asm you wanted. give it a shot, you might get lucky