Tests/Complex: Replace exec_program() with execute_process()

Tests/Complex/CMakeLists.txt

@@ -327,12 +327,12 @@ if (WIN32)
       ${Complex_SOURCE_DIR}/Library/dummy
       "${dir}/${file}"
       COPYONLY)
-    exec_program(${CMAKE_COMMAND} ARGS "-E write_regv \"${hkey}\" \"${dir}\"")
+    execute_process(COMMAND ${CMAKE_COMMAND} -E write_regv "${hkey}" "${dir}")
     find_path(REGISTRY_TEST_PATH
       ${file}
       "[${hkey}]" DOC "Registry_Test_Path")
-    exec_program(${CMAKE_COMMAND} ARGS "-E delete_regv \"${hkey}\"")
-    exec_program(${CMAKE_COMMAND} ARGS "-E rm -f \"${dir}/${file}\"")
+    execute_process(COMMAND ${CMAKE_COMMAND} -E delete_regv "${hkey}")
+    execute_process(COMMAND ${CMAKE_COMMAND} -E rm -f "${dir}/${file}")
   endif ()
 endif ()