Update subform table field

[sd_eds]

I have an odd question but here goes.

I have an employment database with a form and subform. The main form
contains the applicant data and the subform contains information about
the position they are applying for. That table is called
tblApplication. The table has 3 hidden and 3 visible fields. The
hidden fields are Id, HomePhone, and Position (Position is essentially
the PositionID from the Position table). The visible fields are
PositionInformation, Interviewed, and Notes. The PositionInformation
field contains the PositionID, Description, and PositionDate from the
Position table, in that order.

The PositionInformation field is a lookup field and when the HR person
selects a position and adds in the other information regarding he
applicant, tblApplication automatically gets filled with that record
information. Everything except for Position which stays blank. Is
there a way to update that field when PositionInformation is selected?
I have tried = Left([tblApplications]![PositionInformation], 1) but
that does not seem to do it. I dont want to have the HR person select
the position twice in the subform.

Thanks in advance.