I want to call MASM functions with Inline or macro

Question

I would like to be able to Inline MASM Functions in C code like this:

<myfunction.asm> 
myfunction macro
    ...
myfunction endm

<main.c>
int main()
{
   myfunction;
}

can call it using extern "C" but then MyFunction will be called in many places with one Address. I want to embed new code like a macro where MyFunction is called. Is this possible?