matrix from columns

Hello everybody !

First, sorry for my poor english, but my first language is french

Well, I have to create a matrix from columns in this format :

A1 A2 1
A1 A3 4
A1 A4 6
A1 A8 4
A2 A5 2
A2 A8 3

with a lot of empty cells (here, for exemple A1,A6 & A1,A7 ) and (A1,A2) = (A2,A1)

I'd like to have :

_ A1 A2 A3 A4 A5 A6 A7 A8 .....
A1 0 1 4 6 0 0 0 4
A2 1 0 0 0 2 0 0 3
etc

The source data is in the attachment.

Would it be possible to do it automatically ?

Many thanks in advance !