Employee advance, expense claim and payment entry

I need suggestions and some explanation on how ERPNext accounting works.

Here’s the case:

  1. Employee takes advance - Rs. 100,000.00 for purchase (not personal but for office expense) of (let’s say) a “Table”.
  2. This is registered as employee advance.
  3. Next, he submits the purchase receipt and lets say the total cost is 90,000 and the employee returns remaining 10,000 to the office. The table is delivered to the office. Everything is clear.
  4. How to book every of these transactions ?
    a. Create a PO, PR , PI and then enter the 90,000 payment as payment to the party ?
    b. Let the employee claim expense in HR module ?

In expense claim we cannot pull item list from Item Doctype. So, stock is not maintained.
Or should I create PO against the purchase, and enter the payment 90,000 and then again let employee enter Expense claim ? Doesnot the cost be recorded twice ?

I could not grasp this concept. Can some one clarify this please ?