may be try this ( modify for LOG file ):

Code
int mergeAdv(){
    char name1[40],name2[40],name3[40],name4[40];
    char cOut[40];
    
    sprintf(name1,"Data\\1_%s_%s.c",cSystem,strx(Asset,"/",""));
    sprintf(name2,"Data\\2_%s_%s.c",cSystem,strx(Asset,"/",""));
    sprintf(name3,"Data\\3_%s_%s.c",cSystem,strx(Asset,"/",""));
    sprintf(name4,"Data\\4_%s_%s.c",cSystem,strx(Asset,"/",""));
    sprintf(cOut,"Data\\%s_%s.c",cSystem,strx(Asset,"/",""));

    printf("\nSave from %s to %s",name1,cOut);

    if(!file_date(name1)) 
        return 0; // file does not exist

    if(!file_copy(cOut,name4))
        return 0;
    if(!file_append(cOut,file_content(name3))) 
        return 0;
    if(!file_append(cOut,file_content(name2))) 
        return 0;
    if(!file_append(cOut,file_content(name1))) 
        return 0;
  return 1;
}

    if (Train)
    if (is(EXITRUN) )
        mergeAdv();