Copy the Code:

Private Sub CommandButton1_Click()
'selecting of cells from range c3 to till the end of 3rd row across the columns
Range(Range("C3"), Range("C3").End(xlToRight)).Columns.Select
End Sub

'Range("C3").End(xlToRight)).Columns.Select

It denotes from the C3 cell to till the end all the cells will select

Properties and Methods Used:

Select Method
end(xltoright) Method
Columns Property
Range Method

2)Slection from cell to cell - Top to Bottom

Private Sub CommandButton1_Click()
'Select down cells starting from B4
Range(Range("B4"), Range("B4").End(xlDown)).Select
End Sub

3)Select all Cells

Copy the Code:

Private Sub CommandButton1_Click()
Dim d As Long, w As Integer
d = Range(Range("A1"), Range("A1").End(xlDown)).Rows.Count
w = Range(Range("A1"), Range("A1").End(xlToRight)).Columns.Count
Range(Cells(1, 1), Cells(d, w)).Select
End Sub

For rows assign data type as LONG

Variable "d" returns rows count starting from "A1" to till the end., i.e last data cell

Variable "w" returns columns count starting from "A1" to till the end., i.e last data cell

4)Select 3rd row in SELECTED RANGE

5)Select from specific cell to till the end(down):