Dynamically adding nested loops - excel

Question

I have an 'X' amount of variables (likely to range between 3 to 20 options), which will be combined to calculate all possible combinations to meet a criteria. For every extra variable an extra loop is introduced, however I do not know if it possible to make the creation of loops dynamic (in excel VBA, the code doesn't have to be very fast).
To demonstrate:
I have var. A with h = 2, var. B with h = 3.
I would like to know all combinations which are equal to 10 or the best combination of the 2 variables.
In this case: option 1 = 5*A = 10, 3*B = 9,2*A and 2*B = 10, 3*A and 1*B = 9.
The code looks like this:
For A = 0 to 5
h = 0 'Reset previous h if solution is found
For B = 0 to 5
h_test = A * height(A) + B * heigth(B)
if h_test > 10
if h = 0 then
exit for
else
write h
exit for
end if
h = h_test
Next B
Next A
If another parameter is introduced (for example C = 4), the code is:
For A = 0 to 5
h = 0 'Reset previous h if solution is found
For B = 0 to 5
h = 0 'Reset previous h if solution is found
For C = 0 to 5
h_test = A * height(A) + B * heigth(B) + C * heigth(C)
if h_test > 10
if h = 0 then
exit for
else
write h
exit for
end if
h = h_test
Next C
Next B
Next A
In other words, I would like to know if it is possible to translate the pseudocode to real code:
For #parameter. = X
For loop1 = 1 to 5
h = 0
For loop2 = 1 to 5
h = 0
....
For loopX = 1 to 5
h_test = loop1 *parameter1 + loop2 * parameter 2 ...
+ loopX * parameter X
If h_test > 10
Somecode
exit for
End if
Next X
...
Next loop2
Next loop1

Answer 1

There are two distinct problems here. You didn't mention the first, and that is you also need to calculate a value with an indeterminate number of arguments. For that, you can use a ParamArray.
For example:
Public Function Sum(ParamArray args() As Variant) As Long
Dim i As Long
Dim operand As Integer
Dim result As Long
For i = LBound(args) To UBound(args)
result = args(i) + result
Next i
Sum = result
End Function
Which can be used and tested like this:
Public Sub Test()
Debug.Print Sum(1,2) '=> 3
Debug.Print Sum(1,2,3) '=> 6
End Sub
So, that takes care of that problem. Now, as for the problem you asked about, we'll take a similar approach. The key is to loop once for each argument you've received.
Public Sub Run()
NestedLoop 1, 2, 3
End Sub
Public Sub NestedLoop(ParamArray args() As Variant)
Dim result As Long
Dim a As Variant
a = args
Dim h_test As Long
Dim i As Long, j As Long
For i = LBound(args) To UBound(args)
For j = 1 To 5
result = 0
h_test = Sum(a)
If h_test > 10 Then
If result = 0 Then
Exit For
Else
Debug.Print result
Exit For
End If
End If
result = h_test
Next j
Next i
End Sub
Public Function Sum(args As Variant) As Long
Dim i As Long
Dim operand As Integer
Dim result As Long
For i = LBound(args) To UBound(args)
result = args(i) + result
Next i
Sum = result
End Function