How to read a vba code of another excel using vba code

R u talking of macros?

Private Sub FindAnswerCmd_Click()
'If the user forgets to write something in the number place-holders,
If aTxt.Text = "" Or bTxt.Text = "" Or cTxt.Text = "" Then
'than tell him
msg = MsgBox("You forgot to enter a number.", vbCritical + vbOKOnly, "Error")
'and exit this sub
Exit Sub
End If
If aTxt.Text = 0 Then
msg = MsgBox("That isn't a quadratic equation, a musn't equal 0.", vbCritical + vbOKOnly, "Error")
aTxt.SetFocus
Exit Sub
Else
'Assigns the values the user gave to a, b and c
a = aTxt.Text
b = bTxt.Text
c = cTxt.Text
'and calculates the discr and the Apex
discr = (b * b) - (4 * a * c)
ApexX = (-b) / (2 * a)
ApexY = -discr / (4 * a)
End If
If discr < 0 Then
Msg3.Caption = "There are no answers for " & a & "x² + " & b & "x + " & c & " = 0." & vbCrLf & vbCrLf & "The coordinates of the apex are (" & ApexX & ";" & ApexY & ")."
ElseIf discr = 0 Then
x = (-b) / (2 * a)
Msg3.Caption = "The answer for " & a & "x² + " & b & "x + " & c & " = 0 is " & x & "." & vbCrLf & vbCrLf & "The coordinates of the apex are (" & ApexX & ";" & ApexY & ")."
ElseIf discr > 0 Then
x1 = (-b - Sqr(discr)) / (2 * a)
x2 = (-b + Sqr(discr)) / (2 * a)
Msg3.Caption = "The answers for " & a & "x² + " & b & "x + " & c & " = 0 are " & x1 & " and " & x2 & "." & vbCrLf & vbCrLf & "The coordinates of the apex are (" & ApexX & ";" & ApexY & ")."
End If