R1C1 and using variable in array formula

[slang]

Hello, been a while.

I am a bit stumped on this and forgive me if it is as simple as a syntax error :)

I have a sheet that fills an array formula down a column of data but the size of the data can change weekly. I need a way to reference the last row in the R1C1 formula so it doesnt play havoc with the array formula. Here is what I got JUST EXPERIMENTIG WITH THE FIRST REFERENCE TO SEE IF IT WILL TAKE IT BUT IT WILL NOT.

Sub junk()
Dim lastrow As Integer
lastrow = Cells(Rows.Count, 1).End(xlUp).Row
Range("u2").Select
Selection.FormulaArray = _
"=IF(RC[-1]>=LARGE(IF(R2C16:R" & lastrow & "c16=RC[-5],R2C20:R2973C20,0),ROUND(COUNTIF(R2C16:R2973C16,RC[-5])/5,0)),""A""," & Chr(10) & "IF(RC[-1]<=SMALL(IF(R2C16:R2973C16=RC[-5],R2C20:R2973C20,99^99),ROUND(COUNTIF(R2C16:R2973C16,RC[-5])/2,0)),""C"",""B""))"
Range("u2").Select
Selection.AutoFill Destination:=Range("u2:u" & lastrow), Type:=xlFillDefault
End Sub

Am I way off base here with the approach or do I have my syntax wrong?:aw
TGIF

[Aflatoon]

What do you mean by "won't take"?

[slang]

What do you mean by "won't take"?

will not compile, expected end of statement.
Dont even know where to look with this one?
Would it be because I am only refering to it by variable in one instence and using actuals in the rest?

[Aflatoon]

I can't see why - it compiles fine.

[slang]

I can't see why - it compiles fine.

Sorry, "brain fart"
I missed a space between the & and the next variable.
Friday.......
Thanks Aflatoon :doh::doh::doh::doh: