Hello everyone!

Hope you can help me on this
Here's the problem: I'm trying to automate wih power BI something that takes me 4 hours to do.

In a first source I get the following information (Excell file)
* Reference number
* Reference date
* Customer
* Country
* Duration in minutes
* Number of days (if = 1, then the problem occurred just at the reference date, otherwise, it lasted for 2, 3 or more days - days are before and on reference date)

So, I'm copy/pasting by hand from another tool the info below in uppercase in order to have a complete table like this:
* Reference number
* Reference date
* Customer
* SUPPLIER (NB: the suppliers I worked with on the reference date)
* Country
* Duration in minutes
* PURCHASE PRICE (average price over the number of days between (reference date - number of days) and (reference date))
* SALE PRICE (same remark)
* Number of days

By launching on PowerBI:
1 * I import my first table.
2 * I import the uppercase elements from the second table.
3 * I made a correspondence table because in my 2 databases, my clients do not have the same name
Still not walking with reports ...
I made a table apart with the days, a table supplier, and I tried all combinations I could ... still not working.

So, I thought a DAX request might help me.

In natural language, that would be:
In the first table, For (Reference Date), for this (Customer), to this (Country)
Please Mr Power BI, give me: the list of (SUPPLIERS) with for each of them, the (SELLING PRICE) and the (PURCHASE PRICE)
and please Mr Power BI, this price should be the average price between (date of reference - number of days) and (date of reference).

Except that in DAX, I could not make it.

So, can PowerBI solve my problem without DAX (in this case, there must be a relationship problem I presume)?
Or should I write a DAX query? And there, I face problems...

Thanking you for your help
In exchange, I know how to make "clafoutis"!
Arnaud