Increment values in a special manner

[shaju]

Hi,
I have a number which goes like XXXXX/dd-mm-yy. What I want is that when this number is entered into a cell and then dragged down, the XXXXX part should get incremented by one number each but the /dd-mm-yy should remain the same. Is it possible...???
TIA

 

[shaju]

Thanks to all Masters...and a special thanks to MrKowz for the description and "comparing examples".