[Boost-users] build Boost on OSX with other sysroot

Hello, I try to build the Boost 1.50 under OSX (10.6), but I need another sysroot version. Because I need a build with i386 and linking again the /Developer/SDKs/MacOSX10.5.sdk/ Default build again the 10.6 SDK works very well. I have added to the bjam command the flag architecture=x86 and toolset=darwin (--with flags, link, etc), but how can I link the Boost libs to the 10.5 SDK? Thanks Phil