Try

=INDIRECT("'" & INDIRECT(LEFT(ADDRESS(1, COLUMN(),4,TRUE),1) & "7") & "'!D" & ROW())

>For your information, CELL("cell") does not bring information from the current cell if the second parameter is omitted, but from the last cell that was changed.
>
>From Help:
>CELL(info_type,reference)
>Reference is the cell that you want information about. If omitted, information specified in info_type is returned for the last cell that was changed.
>
>I'll take this as homework and will report back :) Thanks again.