Order Number formatter

Question

i want to make Stored procedure to get event number count and order number count in ordernumber column of order table .... event number count cames from Event Table with format is like that if there is 10 events already, format is NNN, next event number will be 001 and same with order number count... This is what i work as event count with format NNN in code but i want to make storedprocedure enter image description here