Hi Saras,
I am not sure this is perfect soultion(I am not familiar with regualr expressions that's why) but this works for you.
for($i=0;$i<strlen($str);$i++){
$char=substr($str,$i,1);
if (ord($char)>=48 && ord($char)<=57){
$pos=$i;
break;
}
}
$alphabet=substr($str,0,$i);
$numeric=substr($str,$i,strlen($str)-$i);
Note:$str is the string you want to split
Cheers
Ajay