SD card variable file name

Using Arduino Storage
26

sjn3:

in setup:
char filename[] = "00000000.CSV";

function call:
getFilename(filename);

function:
__ void getFilename(char filename) {__
** DateTime now = RTC.now(); int year = now.year(); int month = now.month(); int day = now.day();*
** filename[0] = '2';**
** filename[1] = '0';**
** filename[2] = year%10 + '0';**
** filename[3] = year%10 + '0';**
** filename[4] = month/10 + '0';**
** filename[5] = month%10 + '0';**
** filename[6] = day/10 + '0';**
** filename[7] = day%10 + '0';**
** filename[8] = '.';**
** filename[9] = 'C';**
** filename[10] = 'S';**
** filename[11] = 'V';**
** return;**
** }**

Hello,

How Can i use this code with DS1302? Can someone help me rewrite this code?

Thanks,
Peter