Want to auto-populate an order form from a storeroom count form

Hi, I have a spreadsheet I use to keep track of weekly sales patterns and use for estimating the amount of a product I would need to order taking into account what I would expect to sell in a given week and what stock I have at present. On the example I've attached, I show where I enter my storeroom count figures, which are organised by supplier and the position in which a particular product appears on the supplier's order form. I have a page which lists the orders by suppliers and which are used to place the orders by e-mail or telephone.

At present I have each supplier section of the order form directly linked to a cell on the storeroom count as per columns K to M on the attached file. However, this means that as products are de-listed by suppliers and extra products become available, I have to edit the formula in each cell as the products now appear in a different position on the storeroom count and may otherwise end up on the order form for a different supplier. I would like to set it up so that I just have to select the supplier name and the table below will automatically fill with the required info, in order of the position they appear on the supplier's form. I'm struggling to combine vlookup and hlookup. Is there a way to do it or do I need to rethink?

Perhaps something like this?

Exactly like that! Thank you so much; I wish I'd sought out a forum a few weeks ago.

A further question if you don't mind; when I enter the formula into my spreadsheet and edit to the row/column numbers I have, I lose the {} marks surrounding the formula and it stops working. When I add them, the formula appears as text in the sheet? Please can you assist?

"{}" sign is for array formula, to show the sign you need to press CTRL-SHIFT-ENTER button together, and that should be works, and then you copied down or cross. Hope it clear