How can load references dll still using MemoryLoadLibrary

[jeffjiang0613]

I have a library named a.dll, a.dll has a reference b.dll.
When I want to use MemoryLoadLibrary to load a.dll, the default references loader is LoadLibraryA, when I changed the loader to my own loader like the code below, it crashed. How to change the return value of MemoryLoadLibraryEx to a value like the return value of LoadLibraryA?

HCUSTOMMODULE LoadLibrary_R(LPCSTR filename, void* userdata)
{
 bool isFound = false;
 for(auto it: names)
{
 if (strcmp(it, filename) == 0){
 isFound = true;
 break;
 }
 }

 if (isFound){
 size_t size;
 auto buffer = readFileToBuffer(filename, &size);
 auto t = (HMODULE)((PMEMORYMODULE)MemoryLoadLibraryEx(buffer, LoadLibrary_R, _GetProcAddress, _FreeLibrary, NULL))->codeBase;
 //still wrong
 //auto t = (HMODULE)MemoryLoadLibraryEx(buffer, LoadLibrary_R, _GetProcAddress, _FreeLibrary, NULL));
 return t;
 }
 else{
 HMODULE result = LoadLibraryA(filename);
 if (result == NULL){
 return NULL;
 }
 return (HCUSTOMMODULE)result;
 }
}