Mac – How to break a spreadsheet containing CSV into multiple columns

Usually one would select the data-type for each imported column as step 3 of 3 of the text-import dialog. To avoid misformatting, just use text as format, and you're good.

However, you seem to use a VBA macro to import your CSV files. So I just recorded such an uncorrupted text import:

With ActiveSheet.QueryTables.Add(Connection:= _
    "TEXT;C:\test.csv", Destination:=Range("$A$1"))
    .Name = "test_1"
    .FieldNames = True
    .RowNumbers = False
    .FillAdjacentFormulas = False
    .PreserveFormatting = True
    .RefreshOnFileOpen = False
    .RefreshStyle = xlInsertDeleteCells
    .SavePassword = False
    .SaveData = True
    .AdjustColumnWidth = True
    .RefreshPeriod = 0
    .TextFilePromptOnRefresh = False
    .TextFilePlatform = 850
    .TextFileStartRow = 1
    .TextFileParseType = xlDelimited
    .TextFileTextQualifier = xlTextQualifierDoubleQuote
    .TextFileConsecutiveDelimiter = False
    .TextFileTabDelimiter = False
    .TextFileSemicolonDelimiter = True
    .TextFileCommaDelimiter = False
    .TextFileSpaceDelimiter = False
    .TextFileColumnDataTypes = Array(2, 1) 'THIS IS THE MAGIC LINE!
    .TextFileTrailingMinusNumbers = True
    .Refresh BackgroundQuery:=False
End With

Also, look at this example from excel-help for TextFileColumnDataTypes:

Set shFirstQtr = Workbooks(1).Worksheets(1) 
Set qtQtrResults = shFirstQtr.QueryTables _
        .Add(Connection := "TEXT;C:\My Documents\19980331.txt", _
        Destination := shFirstQtr.Cells(1, 1))
With qtQtrResults
    .TextFileParseType = xlFixedWidth
    .TextFileFixedColumnWidths = Array(5, 4)
    .TextFileColumnDataTypes = _
        Array(xlTextFormat, xlSkipColumn, xlGeneralFormat)
    .Refresh
End With

These are the formats you can use:

• xlGeneralFormat
• xlTextFormat
• xlSkipColumn
• xlDMYFormat
• xlDYMFormat
• xlEMDFormat
• xlMDYFormat
• xlMYDFormat
• xlYDMFormat
• xlYMDFormat

Another name for scatter chart is XY chart. This type of graph plots Y values against X values, so both are required. The X axis is a continuous numerical value and something needs to define where to place values along it. On something like a line chart, the X values are just categories, so what goes on the X axis doesn't need to be explicitly defined (successive entries are just stacked next to each other). With a scatter chart, when you select just Y values, Excel uses some kind of built-in rule to define something for X values.

To plot what you are looking for, enter each dataset as a separate data series. You can enter X and Y columns to create the first series, then add each remaining series. Or, highlight the three Y columns to get the process started and then edit each data series to add the X values.

By default, Excel will use a different marker symbol for each series and will create a legend. You can delete the legend and edit the marker symbols so they all match.

If you want to have Excel handle this as a single series using its default settings, you would need to copy the data to a new structure where you actually arranged all of the data into one X and one Y column.