Opening SD file with variable name

Using Arduino Storage
2

In preamble:

char filename[] = "00000000.CSV";
File myFile;

In Setup:

    getFileName();
      lcd.setCursor(0,3); 
      lcd.println(filename);

Srtn:

void getFileName(){
sprintf(filename, "%02d%02d%02d.csv", year, month, day);
}

Write srtn:

void WriteSD()
{  
       myFile = SD.open(filename, FILE_WRITE);//<<<<<<<<<<<<< OPEN
  myFile.print(DrainTemp);
  myFile.print(",");
  myFile.println(ShrTemp);
       myFile.close();//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>CLOSE