Give this a try
Sub TestMacro()
Const cAcct As String = "Acct"
Const cSnbr As String = "SNbr_Acc"
Dim accNum As Long, n As Long
Dim serNum As Long
Dim arrResults()
With Worksheets("Sheet1")
If Not IsNumeric(.Cells(1, "C")) And Not IsNumeric(.Cells(2, "C")) Then Exit Sub
ReDim arrResults(1 To Rows.Count, 1 To 2)
For accNum = 1 To .Cells(1, "C")
For serNum = 1 To .Cells(2, "C")
n = n + 1
arrResults(n, 1) = cAcct & accNum
arrResults(n, 2) = cSnbr & accNum & "_" & serNum
Next
Next
End With
Sheet2.Range("a1").Resize(n, 2) = arrResults
End Sub
Bookmarks