如何在cmake中定义从ExternalProject_add构建的目标派生的变量？

# 添加外部项目
ExternalProject_Add(MyExternalProject
    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/external_project
    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/external_project
    INSTALL_DIR ${CMAKE_CURRENT_BINARY_DIR}/external_project_install
    # 其他配置参数
)

# 获取外部项目的属性
ExternalProject_Get_Property(MyExternalProject INSTALL_DIR)
set(MyExternalProjectInstallDir ${INSTALL_DIR})

# 使用派生的变量
add_executable(MyApp main.cpp)
target_include_directories(MyApp PRIVATE ${MyExternalProjectInstallDir}/include)
target_link_directories(MyApp PRIVATE ${MyExternalProjectInstallDir}/lib)
target_link_libraries(MyApp PRIVATE my_external_library)