VBA Lean Coding: Dynamic Multiple Sheet Vlookup Galore - excel

Question

Code below doesnt run. Poorly done over all. Please let me know if you have any questions. Willing to share file.
In a nutshell, what I am trying to do is as follows:
Source Sheet contains the PO forecast by Month. Output sheet is more organized has the same POs but formatted differently. Check screenshot link below before your brain starts hurting. I need to match the Monthly PO (stands for Purchase Order) forecast by month on the Sourcesheet to the POs by month on the output sheet.
If the outputsheet column E contains text "PO labor or PO materials" Then perform Vlookup, otherwise skip. Vlookup matches the PO monthly forecast in the sourcesheet to the output sheet. values must be matched to the month. Loop the if then function until end of outputsheet. After finishing copy and paste any cells in the defined output vlookup range to copy and paste value to reduce multiple coding. at the end you will find screen shots.
Sub NB_Run_Forecast_Upload()
Dim rng1 As Range 'Source Sheet this will set the range in which you want this formula to appear
Dim cl1 As Range
Dim rng2 As Range 'Output Sheet
Dim cl2 As Range 'Output Sheet
Dim rng3 As Range 'Outsheet Range for If Then Statement. Col C must have either "PO Labor" or "PO Materials" to execute Vlookup otherwise skip
Dim strFormula1 as String `string to hold the formula text
Dim SourceLastRow As Long
Dim OutputLastRow As Long
Dim sourceSheet As Worksheet
Dim outputSheet As Worksheet
Dim DataValidation As Worksheet
Set sourceSheet = Worksheets("NB & COAX PO Detail test")
Set outputSheet = Worksheets("New Build & Coax test")
Set DataValidation = Worksheets("Data Validation")
Set rng1 = sourceSheet.Range("I5:AB1339") 'Range hardcoded; need it to go to end
Set rng2 = outputSheet.Range("G1:R5000") 'Range hardcoded; need it to go to the end of rng3
Set rng3 = output.Sheet.Range("C1:C5000") 'Range for If Then statement
'nothing happens in sourceSheet. it is basically, the area where information is stored for vlookup
On Error Resume Next
With sourceSheet 'this might be a double declaration as rng1 does declare
SourceLastRow = .Cells(.Rows.Count, "I").End(xlUp).Row
End With
With outputSheet
'if statement to check if Col C contains either "PO Labor" or "PO Materials"
For Each cl1 In rng2 'my translation: for each cell in rng2 perform the below
If rng3.Value = "PO Materials" Then 'i would prefer to add OR statement to add "PO Labor" reduce redundancy
cl2.Forumla = MyLookupFormula
Else
If rng3.Value = "PO Labor" Then
c2.Forumla = MyLookupFormula
End If
Next rng2 'next col same row until after same row Col R it goes down the row in the outputsheet
End With
Function Colindexnum() As Integer 'i coded the Col number referenec for each month in the Outputsheet that corresponds to the same month in the Sourcesheet
'it's similar to =vlookup(A1, A2:C2, ColIndexNum,0) ColIndexNum changes to each month, its constant in the outputsheet but changes in the sourcesheet
'because every time period a month is deleted. final range is till Dec
Colindexnum = (Application.WorksheetFunction.VLookup(outputSheet.Range("G3:R3"), DataValidation.Range("H30:I41"), 2, False))
End Function
Function MyLookupFormula() As Variant
If Not IsError(Application.WorksheetFunction.VLookup(outputSheet.Range("E:E"), rng1, Colindexnum, False)) Then
MyLookupFormula = (Application.WorksheetFunction.VLookup(outputSheetRange("E:E"), rng1, Colindexnum, False))
Else: MyLookupFormula = vbNullString
End Function
'after each lookup I want to copy and paste the cell it looked up to avoid too much coding Rng2
With outputSheet
For Each rng2 In .UsedRange
If rng2.Formula Like "*VLOOKUP*" Then rng2.Formula = rng2.Value
Next rng2
End With
End Sub
(Output Sheet & Source Sheet Click the next image) http://imgur.com/SHANSLF&ydjQfb3#0

Answer 1

Finally finished this with the help of several genereous memebers of this community and Chandoo. here is the final code that I put together and that actually works.
Sub MakeFormulas()
Dim SourceLastRow As Long
Dim OutputLastRow As Long
Dim sourceSheet As Worksheet
Dim outputSheet As Worksheet
Dim X As Long
Dim Z As Long
'What are the names of our worksheets?
Set sourceSheet = Worksheets("Sheet1")
Set outputSheet = Worksheets("Sheet2")
'Determine last row of source
With sourceSheet
SourceLastRow = .Cells(.Rows.Count, "A").End(xlUp).Row
End With
With outputSheet
'Determine last row in col C
OutputLastRow = .Cells(.Rows.Count, "C").End(xlUp).Row
For y = 17 To 28 'Q to AB
For X = 2 To OutputLastRow
If InStr(1, .Range("C" & X), "PO Materials") + InStr(1, .Range("C" & X), "PO Labor") > 0 And Cells(2, y) = "Forecast" Then
'Apply formula
.Cells(X, y).Value = _
Evaluate("=VLOOKUP($E" & X & ",'" & sourceSheet.Name & "'!$A$2:$L$" & SourceLastRow & ",Match(" & Cells(1, y).Address & ",'" & sourceSheet.Name & "'!$A$1:$AD$1,0),0)")
End If
Next
Next
End With
End Sub