How do I use data from other fields in a found record

[A.J.M. van Rijthoven]

I have a table instrumenten (INSID Instrumentname, CATID), a table
Categorie (CATID, Categorydescription), Netten (NETID, description of
net) and a table (kpltblinstrument) that links the instruments to a
specific net (NETID, INSID, amount).
I have a form which displays the name of the net and it holds a the
subform from table lnknetins. I have two unlinked fields (combobox) on
the form (voorlopigcategorie and voorlopiginstrument). When I select a
category, the following code provides a query for the
voorlopiginstrument combobox.

If voorlopigcategorie.Text = "-" Then
PublicSql = "SELECT
Instrumenten.instrumentnaam,instrumenten.insid, Instrumenten.categorie
FROM Instrumenten;"
Else
PublicSql = "SELECT
instrumenten.Instrumentnaam,instrumenten.insid, instrumenten.Categorie
FROM instrumenten WHERE
(((instrumenten.Categorie)=[Forms]![Inhoud_van_net]![voorlopigcategorie].[value]));"
End If
voorlopiginstrument.RowSource = PublicSql

Now I want to fill the field INSID on my subform with the INSID from
the selected instrument in voorlopiginstrument.
Voorlopiginstrument.value only gives me the name of the instrument and
not the INSID.
How do I do this??

Simplified:
I've looked up a record in a table based on a name and now I want to
use another field of the found record and place its value in another
record. How do I do this??

 

[Ken Snell]

Reference the column of the combo box and you can get it. In this case,
INSID is the second column/field of the combo box row source query, right?
Column is a zero-based property, so you can get the value of the second
column using this expression:

ValueOfSecondColumn = Me.voorlopiginstrument.Column(1)