Work Order and Job Card traceability

Hello Everyone,

        I recently installed the ERPNext  and I have question regarding job cards, 
    Our each work order has many operations and each work order creates multiple job cards, 

I would like to have sequence number on each job card.

example - Work order number = 1800
Job card numbers should start with same number =1800 (which is can be done with naming series)
then each Job card should have =1800 A, 1800 B, 1800 C … naming series

Next work order =1801
job cards =1801 A, 1802 B …

it will make easier traceability, and easier for the employees to find out the correct job card

Please advise, thank you