add cmd target to deal with corner case operations

Makefile

@@ -316,11 +316,14 @@ endif
 	desktop/scripts/soffice.sh ooo.lst post_download post_download.log \
 	config_host.mk.last set_soenv.stamp src.downloaded warn
 
-# The real targets are in solenv/gbuild/Module.mk, resp.
-# solenv/gbuild/extensions/post_BuildplTargets.mk, this file only forwards
-# the calls - please look there if you want to edit what this toplevel
-# Makefile does.
+#
+# custum command
+#
+ifneq ( $(MAKECMDGOALS),cmd)
+cmd:
+	echo "custum cmd" && ( $(cmd) )
 
+endif
 
 #
 # Bootstap