Excel VBA - Formula writing error - vba

Question

I am trying to bring a formula inside my vba code and I am getting an error inside it. Please have a look into the code and kindly share your thoughts.
This is my excel function that was written in VBA Code :
GetUniqueCount(Range,Value)
And here is the VBA Code trying to make use of it :
Sheets("sheet2").Activate
With ThisWorkbook.Sheets("sheet2").UsedRange
lastrow = .Rows(.Rows.Count).Row
End With
For i = 14 To lastrow
check = Range("h" & i).Value
If check <> "" Then
Range("I" & i).Value = WorksheetFunction.GetUniqueCount(sheet1!.Range("A1:B100"), check)
Else
Range("I" & i).Value = ""
Next
The range for the function comes from a different sheet. How do I write it in VBA?
This is the function for it :
Function GetUniqueCount(Rng1 As Range, Lookup As String) As Long
Dim x, dict
Dim i As Long, cnt As Long
Set dict = CreateObject("Scripting.Dictionary")
x = Rng1.Value
For i = 1 To UBound(x, 1)
If x(i, 1) = Lookup Then
dict.Item(x(i, 1) & x(i, 2)) = ""
End If
Next i
GetUniqueCount = dict.Count
End Function

Answer 1

You have other possible errors in your code, unqualified Range, etc.
Since your Function GetUniqueCount is not Excel's built in WorksheetFunction, but your own UDF, you don't need to call it with WorksheetFunction.GetUniqueCount but just GetUniqueCount.
Try the code below:
Option Explicit
Sub Test()
Dim LastRow As Long, i As Long
Dim check As String
With ThisWorkbook.Worksheets("sheet2")
LastRow = .Cells(.Rows.Count, "I").End(xlUp).Row
Dim Rng As Range
Set Rng = Worksheets("sheet1").Range("A1:B100")
For i = 14 To LastRow
check = .Range("H" & i).Value
If check <> "" Then
.Range("I" & i).Value = GetUniqueCount(Rng, check)
Else
.Range("I" & i).Value = ""
End If
Next i
End With
End Sub

Answer 2

There is no worksheet function by the name of GetUniqueCount. If this is a function you have in your code then the way to call it would be like this:-
Range("I" & i).Value = GetUniqueCount("Sheet1".Range("A1:B100"), check)
This code presumes that your function is either on the same code sheet as the calling procedure or declared public. It must take two arguments, the first of which must be a range, the second of the same data type as check. If you didn't declare check (which isn't a good idea) then its data type will be Variant.