Is there a way to pass linker commands to CMake on the command line?  I could try doing it that way.

You could declare the static library as imported and use this target for dependencies - from StackOverflow:

# Your-external "mylib", add GLOBAL if the imported library is located in directories above the current.
add_library( mylib SHARED IMPORTED )
# You can define two import-locations: one for debug and one for release.
set_target_properties( mylib PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/res/mylib.so )

But it's possible to force FindBoost to use static versions - just set:

    set(Boost_USE_STATIC_LIBS ON)

before using

    find_package(Boost ......)

Hope it helps,

Leon