use $(CURDIR) instead of "..\..\.." because the later does not allow to use options as --with-zlib=../zlib-1.2.3. It seems there is no common way to learn the current directory in Win32 make's: although nmake has MAKEDIR variable, nevertheless Borland make's MAKEDIR is the directory where make is installed, and OpenWatcom wmake has no MAKEDIR at all.

--- a/auto/make
+++ b/auto/make
@@ -22,6 +22,7 @@ CC =	$CC
 CFLAGS = $CFLAGS
 CPP =	$CPP
 LINK =	$LINK
+CURDIR = `pwd`
 
 END