cast access text to numeric

[TheBellonz]

I'm working in access 2007. I have a couples of tables that I've imported from Excel in the link mode, so access makes a copy of them and I can use them just in read mode. Now I'm in a trouble with a cast. The primary key is text in the first table and integer in the other one. I want to make the first one like a numeric field.

I assume the left table like "Lansweeper_jacopoBelloni" and as the right table "PC_CarelHQ_modificato". I have to do 3 queries, one with a inner join because there must be a (1,1) relation beetween the two tables. A right join to check what there is in the left table that there is also in the right one. Finally I have to do a left join to find what in the right table is also in the left one. Thanks in advance