Getting macro to return input made into input box

Hi i am very new to excel macros and i am very lost. I am trying to get a macro to calculate the sum of a number of cells and from that calculate an escalation based on the input made into an input box.. this is working fine but i need to get the macro to return the input made into the input box in the cell below with a percentage symbol. This i can't figure out.. This is what i've tried..

  Dim intEscRate As Integer
    intEscRate = InputBox("Enter an escalation percentage: ")
    ActiveCell.FormulaR1C1 = "=SUM(R[-4]C+R[-3]C+R[-2]C)"
    ActiveCell.Offset(1, 0).Range("A1").Select
    ActiveCell.FormulaR1C1 = "=R[-1]C*1." & intEscRate & ""
    ActiveCell.Offset(1, 0).Range("A1").Select
    ActiveCell.FormulaR1C1 = Val("intExcRate")
    ActiveCell.Offset(1, 0).Range("A1").Select

It's the last two lines that aren't right. For example if i put 25 into the inpur box i need the macro to put 25% into the cell below the other two values.

Can anyone help me please??