use sfdisk to create scripted partitions

sfdisk.sh

##create one big partition
echo ';' | sfdisk /dev/sdc

##create one big partition with specific partition type
#creates W95 FAT32 (LBA)
echo ',,c;' | sfdisk /dev/sdd

#creates lvm type
echo ',,8e;' | sfdisk /dev/sdd

##Three primary partitions: two of size 50MB and the rest:
sfdisk /dev/hda -uM << EOF
,50
,50
;
EOF

##A 1MB OS2 Boot Manager partition, a 50MB DOS partition, and three extended partitions (DOS D:, Linux swap, Linux):
sfdisk /dev/hda -uM << EOF
,1,a
,50,6
,,E
;
,20,4
,16,S
;
EOF

#Useful commands
sfdisk -l /dev/hda     #list partitions
sfdisk -l -x /dev/hda  #list extended partitions
sfdisk -T              #list partition types

Hello,
is it possible to use sfdisk to create an extended partition on a left free space on a disk ?

thanks