Columns is a member of Application, OfficeDataSourceObject, Range,
Worksheet. Excel is a Library.

You can only resize UsedRange by using more or fewer cells. It is a
read-only property.

From Excel Help, one unit of ColumnWidth is equal to the width of one
character in the Normal style. For proportional fonts, the width of
the character 0 (zero) is used.

When Application.WindowState = xlNormal, it can be resized as follows
(change numbers to suit).
Application.Left = 193.75
Application.Top = 1.75
Application.Width = 574.5
Application.Height = 552.75

Hth,
Merjet