Bill,

I am not 100% clear what you mean.  Maybe a specific example would help.
 But it could be that an Update Query is what you are looking for?
UPDATE YourTable SET YourField = "something" WHERE ID = x

There is no canned function like DLOOKUP, but you could use:

Public Function fnPut(Fieldname as string, Tablename as string, _
                                SomeValue as Variant, Optional Criteria as
Variant = NULL) as boolean

   Dim strSQL as string
   Dim rs as DAO.Recordset

   On Error GoTo fnPutError

   strSQL = "SELECT [" & Fieldname & "] " _
               & "FROM [" & Tablename & "] " _
               & ("WHERE " + Criteria)
   set rs = Currentdb.openrecordset (strsql, , dbfailonerror)

   While not rs.eof
        rs.edit
        rs(Fieldname) = SomeValue
        rs.update
        rs.movenext
   Wend
    fnPut = true

fnPutExit:
    if not rs is nothing then
        rs.close
        set rs = nothing
   endif
   Exit Function
fnPutError:
   msgbox err.number & err.description, vbInformation + vbOkOnly, "Error:
fnPut"
   fnPut = false
   Resume fnPutExit
End sub

I use a function that looks like this, although I don't have access to it at
the moment (this is air code, so you might run into a bug or two).

While this is slower than an UPDATE statement especially if the criteria
returns multiple values, you avoid having to deal with making sure you have
your SomeValue parameter in the right format.  This will return a true if
the update worked and a false if an error was generated.

HTH
Dale