Help : Apply formula to selected cells

Hi,

My code below while applying the input formula in selection, converts the existing value to a result. How to avoid that ?
If I change myCell.Value to myCell.Formula, it is resulting in error

For example in one cell I have a value of =10+20 and then if I apply the code with an input formula of *10. The result will be =(30)*10
But I need the result to be like =(10+20)*10
Also how to exclude the hidden rows and columns while running the code

Code:

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Option Explicit


Sub ApplyFormula()


Dim myRange As Range
Dim myCell As Range
Dim InputFormula As String


    Select Case MsgBox("You Can't Undo This Action. " & "Save Workbook First?", vbYesNoCancel, "Alert")
        Case Is = vbYes
        ThisWorkbook.Save
        Case Is = vbCancel
        Exit Sub
    End Select
Set myRange = Selection
InputFormula = InputBox("Enter formula to apply")
Application.ScreenUpdating = False
For Each myCell In myRange
    If Not IsEmpty(myCell) Then
    myCell.Value = "=(" & (myCell.Value) & ")" & InputFormula
End If
Next myCell
Application.ScreenUpdating = True


End Sub

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Thanks in advance for your help

To only loop trough visible cells in your range, use:

Code:

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For Each myCell In myRange.SpecialCells(xlCellTypeVisible)

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For the other art of your question, using myCell.Formula instead of myCell.Value will probably help. Though you'll have to remove the equal sign if using the existing formula within another. Something like:

Code:

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myCell.Formula = "=(" & Replace(myCell.Formula, "=", "", 1, -1, vbBinaryCompare) & ")" & InputFormula

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Note that you'll run into trouble if you use an equal sign other places than at the start of the formula using this method, in that case

Code:

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Right(myCell.Formula, Len(myCell.Formula) - 1)

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might be a better choice for what to put into the parentheses. This will however break if there *isn't* an equal sign at the start of the formula. It shouldn't be too hard to foolproof this a bit further, but I'll leave that as an exercise to the reader. I think what I have included here should give you a good starting point at any rate.

Thanks EirikDaude

For the time being, the following code is fine as there wont be an equal sign in other than at the start of the formula

Code:

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myCell.Formula = "=(" & Replace(myCell.Formula, "=", "", 1, -1, vbBinaryCompare) & ")" & InputFormula

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