There was already a thread about this, in lite-C structs are somewhat similar to classes. You can call functions from structs, but you must use a pointer to the struct. This works:

Code:
typedef struct
{
  void fn(char* text);    
} TEST;

void func(char* text)    //your function
{
  printf(text);
}

TEST test;

void main()
{
  TEST* t = &test;
  t->fn = func;  
  t->fn("Hello world!");   
}