Assuming that 2 variables are added, then * 1.1, you can send in a
ParamArray and loop through it. You may have to change the calculation, or
allow odd number of inputs depending on your requirements. Something like:

Private Function igst(taxRate As Single, ParamArray Inputs() As Variant) As
Variant
Dim i As Long
Dim RunTot As Single
'Check if even number of elements in paramarray
If (UBound(Inputs) - LBound(Inputs)) Mod 2 < 1 Then
igst = CVErr(xlErrNum) 'Or other error
Exit Function
End If

For i = LBound(Inputs) To UBound(Inputs) Step 2
RunTot = RunTot + (Inputs(i) + Inputs(i + 1)) * taxRate
Next
igst = RunTot
End Function

Private Sub CommandButton1_Click()
MsgBox igst(1.1, 10, 20, 30, 40, 50, 60, 70, 80)
End Sub

NickHK

"Santa-D" wrote in message
oups.com...
What if the array is larger than 4 variables?

Let's say there is 6 or 8 or 12 variables?

It would be stupid to go

Dim var1, var2, var3, var4.....var99 ?

I guess what I'm trying to do is define an array of values that is
input via the var1,2,3,4 and then return a single string.

i.e.

igst($200,$300,$400,$500) = $1540
at the same time I could do
igst($200) = $220



jseven wrote:
You were getting there. Problem is you have to define each variable.
This will allow you to enter the formula as you wish. Then you have to
return the result to the function by saying "igst = result"

Function igst(var1 As Double, var2 As Double, var3 As Double, var4 As
Double)

igst = ((var1 + var2) * 1.1) + ((var3 + var4) * 1.1)

End Function

Regards,
Jamie