How to call a function from an already injected dll(c++)?

Question

how do I call a function within a DLL already injected into the process? example: I would like when I press a button on the form I created, to call the asmFunction() function; if I call the function inside the main_thread works very well, but I doubt to do it Here is the code of my dll.

#include <Windows.h>
extern int UiMain();
DWORD WINAPI Main_Thread(LPVOID lpParam) {
    UiMain();
    return S_OK;
}
void asmFunction(DWORD x,DWORD y,DWORD adressToCall) {
    __asm {
        push x
            push y
            call adressToCall
    };
}
BOOL APIENTRY DllMain(HMODULE hModule,DWORD _reason,LPVOID lpReserved) {
    if (_reason == DLL_PROCESS_ATTACH) {
        CreateThread(0, 0x1000, &Main_Thread, 0, 0, NULL);
    }
    return TRUE;
}