I want to add icon to my application in windows XP,

I am using QT4.6.2 and mingwin that comes with it.
I have a folder called "res" in the same folder that .pro file exists. there is a .res file with icon info
NM.ico is also placed in "res" along with qrc file

when I add RC_FILE = res/nm.rc or RC_FILE = $${PWD}/res/nm.rc or even if I type the full path qmake adds this line to the generated "Makefile"
windres -i res\nm.rc -o debug\nm_res.o --include-dir=./res

note that ${PWD} is somehow changed from full path (which documents says it should be) to a simple "."
This causes problem because "windres" does not know how to locate the icon and crashes, while if it was the full path there was no problem.
I can run windres with full path but needs me to change the makefile every time that I change the pro file!

Is there any workarounds?