Finding and Replacing with Subscripts

Evan has a worksheet that contains a number of chemical compound notations, such as H2O. When he firsts enters the compound, he can format the 2 as a subscript, as it should be. However, Evan needs to search for instances where the 2 is not subscripted and replace it with the correctly subscripted notation. He wonders if there is an easy way to do this.

There is no way to do this using the Find and Replace features of Excel. The reason? As one ExcelTips subscriber put it, "Excel is spectacularly bad at handling rich text in cells." Evidence of this is the very fact that you cannot search for mixed formatting within a cell or replace with mixed formatting.

Note that I said "mixed formatting," which is what Evan wants—the "H" and "O" use different formatting than the "2". If Evan had wanted to change the entire cell contents to regular text or to subscribe, then you could have used the regular Find and Replace tool. It won't work for mixed formatting, though.

This means that the best approach is to use a macro to do the finding and replacing. There are several ways you can approach this; the following is just one.

Sub SubscriptNumbers()
    Dim c As Range
    Dim sWord As String
    Dim sChar As String
    Dim x As Long

    For Each c In Selection
        sWord = c.Value
        For x = 1 To Len(sWord)
            sChar = Mid(sWord, x, 1)
            If sChar >= "0" And sChar <= "9" Then
                c.Characters(Start:=x, Length:=1).Font _
                  .Subscript = True
            End If
        Next x
    Next c
    Set c = Nothing
End Sub

To use the macro, select the cells you want to modify and then run it. It steps through each cell in the selection and then examines the cell contents. If there are any digits in the contents, then those digits are formatted as subscript.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (13362) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and 2021.