Items.CellMerge Property (ExplorerTree)

Use the CellMerge property to combine two or more cells in the same item in a single cell. The data of the source cell is displayed in the new larger cell. All the other cells' data is not lost. Use the ItemDivider property to display a single cell in the entire item. Use the UnmergeCells method to unmerge the merged cells. Use the CellMerge property to unmerge a single cell. Use the MergeCells method to combine one or more cells in a single cell.

The following sample shows few methods to unmerge cells:

With ExplorerTree1.Groups(0)
    With .Items
        .UnmergeCells .ItemCell(.RootItem(0), 0)
    End With
End With

With ExplorerTree1.Groups(0)
    With .Items
        Dim r As Long
        r = .RootItem(0)
        .UnmergeCells Array(.ItemCell(r, 0), .ItemCell(r, 1))
    End With
End With

With ExplorerTree1.Groups(0)
    .BeginUpdate
    With .Items
        .CellMerge(.RootItem(0), 0) = -1
        .CellMerge(.RootItem(0), 1) = -1
        .CellMerge(.RootItem(0), 2) = -1
    End With
    .EndUpdate
End With

You can merge the first three cells in the root item using any of the following methods:

 With ExplorerTree1.Groups(0)
    With .Items
        .CellMerge(.RootItem(0), 0) = Array(1, 2)
    End With
End With

With ExplorerTree1.Groups(0)
    .BeginUpdate
    With .Items
        Dim r As Long
        r = .RootItem(0)
        .CellMerge(r, 0) = 1
        .CellMerge(r, 0) = 2
    End With
    .EndUpdate
End With

With ExplorerTree1.Groups(0)
    .BeginUpdate
    With .Items
        Dim r As Long
        r = .RootItem(0)
        .MergeCells .ItemCell(r, 0), .ItemCell(r, 1)
        .MergeCells .ItemCell(r, 0), .ItemCell(r, 2)
    End With
    .EndUpdate
End With

With ExplorerTree1.Groups(0)
    With .Items
        Dim r As Long
        r = .RootItem(0)
        .MergeCells .ItemCell(r, 0), Array(.ItemCell(r, 1), .ItemCell(r, 2))
    End With
End With

With ExplorerTree1.Groups(0)
    With .Items
        Dim r As Long
        r = .RootItem(0)
        .MergeCells Array(.ItemCell(r, 0), .ItemCell(r, 1), .ItemCell(r, 2))
    End With
End With

		Type	Description
		Item as Variant	A long expression that indicates the item's handle.
		ColIndex as Variant	A long expression that indicates the column's index, a string expression that indicates the column's caption or the column's key.
		Variant	A long expression that indicates the index of the cell that's merged with, a safe array that holds the indexes of the cells being merged.