You can insert blank cells into a range using the insert into range command, which is the equivalent of the Visual Basic for Applications (VBA) Insert method, as long as there is room to do so without moving populated cells off of the worksheet. It is just like the Insert > Rows, Columns, or Cells menu in the UI. In VBA:

Sheets("Sheet1").Range("B2:B5").Insert Shift:=xlShiftToRight

In AppleScript:

insert into range range "B2:B5" shift shift to right

In VBA, if a range has been copied and the Insert method applies to a range of the same size, the clipboard contents will be copied to the inserted cell.

With ActiveWorkbook
	With Sheets("Sheet2").Range("A1:A10")
	.Copy
	Sheets("Sheet1").Range("B2").Resize( _
		.rows.count, .columns.count).Insert _
		Shift:=xlShiftToRight, _
		CopyOrigin:=xlFormatFromLeftOrAbove
	End With
End With

Here the CopyOrigin argument in VBA has no AppleScript equivalent, so the defaults will rule. If this argument is omitted, the format is inherited as from the Left or Above depending on whether the shift was to the right or down. So there's no way to specify it in AppleScript, but in this case the result will be exactly the same — xlFormatFromLeftOrAbove.

tell application "Microsoft Excel"
	tell active workbook
		tell range "A1:A10" of sheet "Sheet2"
			copy range
			insert into range (get resize row size (count rows) ¬
				column size (count columns)) shift ¬
				shift to right
		end tell
	end tell
end tell