diff --git a/makefile.vc b/makefile.vc
index 0aacbc7..d95d859 100644
--- a/makefile.vc
+++ b/makefile.vc
@@ -7,7 +7,7 @@
 LIBOBJ	               =	freexl.obj
 FREEXL_DLL	 	       =	freexl$(VERSION).dll
 
-CFLAGS	=	/nologo -IC:\OSGeo4W\include -I. -Iheaders $(OPTFLAGS)
+CFLAGS	=	/nologo -I$(INSTALLED_ROOT)\include -I. -Iheaders $(OPTFLAGS)
 
 default:	all
 
@@ -23,9 +23,9 @@ freexl.lib:	$(LIBOBJ)
 $(FREEXL_DLL):	freexl_i.lib
 
 freexl_i.lib:	$(LIBOBJ)
-	link /debug /dll /out:$(FREEXL_DLL) \
+	link $(LINK_FLAGS) /dll /out:$(FREEXL_DLL) \
 		/implib:freexl_i.lib $(LIBOBJ) \
-		C:\OSGeo4w\lib\iconv.lib
+		$(LIBS_ALL)
 	if exist $(FREEXL_DLL).manifest mt -manifest \
 		$(FREEXL_DLL).manifest -outputresource:$(FREEXL_DLL);2 
 
diff --git a/nmake.opt b/nmake.opt
index 35f9242..efb6f77 100644
--- a/nmake.opt
+++ b/nmake.opt
@@ -1,10 +1,10 @@
 # Directory tree where FreeXL will be installed.
-INSTDIR=C:\OSGeo4W
+INSTDIR=$(INST_DIR)
 
 # Uncomment the first for an optimized build, or the second for debug.
-OPTFLAGS=	/nologo /Ox /fp:precise /W3 /MD /D_CRT_SECURE_NO_WARNINGS \
+OPTFLAGS=	/nologo /fp:precise /W3 $(CL_FLAGS) /D_CRT_SECURE_NO_WARNINGS \
 			/DDLL_EXPORT
-#OPTFLAGS=	/nologo /Zi /MD /Fdfreexl.pdb /DDLL_EXPORT
+#OPTFLAGS=	/nologo $(CL_FLAGS) /Fdfreexl.pdb /DDLL_EXPORT
 
 # Set the version number for the DLL.  Normally we leave this blank since
 # we want software that is dynamically loading the DLL to have no problem