Application.Union (Excel)
Returns the union of two or more ranges.
Union (Arg1, Arg2, ..., Arg30)
Worksheets("Sheet1").Activate
Set bigRange = Application.Union(Range("Range1"), Range("Range2"))
bigRange.Formula = "=RAND()"
Arguments
Arg1, Arg2, ..., Arg30Arg1 (Range) - At least two Range objects must be specified.
Arg2 (Range) - At least two Range objects must be specified.
Arg30 - A range