Dim r As Range, j As Long
    Set r = Selection
    j = r.Column
' Определяем адрес столбца выделенной ячейки
    MsgBox j
  For t =  20  To  2  Step - 1 
    If Range("F" & t).Value = "<>Цех1" Then
    Rows(t).Delete
    End If
    Next

Dim r As Range, j As Long
    Rows("1:1").Select
    Selection.Find(What:="Цех", After:=ActiveCell, LookIn:=xlFormulas, _
        LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
        MatchCase:=False, SearchFormat:=False).Activate
    ActiveCell.Select
    Set r = Selection
    j = r.Column
  For t =  20  To  2  Step - 1 
    'If Range("F" & t).Value = "<>Цех1" Then
    If Cells(t, j).Value = "<>Цех1" Then
    Rows(t).Delete
    End If
    Next

Sub Макрос1()
Dim r As Range, j As Long, t As Long
Dim iFind As Range, X As Long

    Set iFind = Rows("X:X").Find(What:="Цех1", LookIn:=xlFormulas, LookAt:=xlPart)
    If iFind Is Nothing Then
        MsgBox "Столбец не найден"
        Exit Sub
    End If
    j = iFind.Column
    For t =  20  To  2  Step - 1 
        If Cells(t, j).Value <> "Цех1" Then
            Rows(t).Delete
        End If
    Next
End Sub

Set iFind = Rows("X:X").Find(What:="Цех1", LookIn:=xlFormulas, LookAt:=xlPart)