Set form.control equal to subfrm.control before update

Here is what i have:
(access 2000)

tblOne: SampleNumber,LinkNumber,LinkSchedule (and other misc)

tblTwo: EmpID,LinkNumber,LinkSchedule (and other misc)

frmOne recordsource = tblOne
subfrmTwo recordsource = tblTwo

When i enter a LinkNumber in frmOne, it filters all of the records in
subfrmTwo with the matching LinkNumber. LinkSchedules will be
different, so there will be multiple entries with the same LinkNumber
in tblTwo. After i enter a LinkSchedule in subfrmTwo, i would like it
to update tblOne.LinkSchedule.

Any thoughts or suggestions?