```
Function VLin_Interp(Entry, Table As Range, Col)
'
' This function performs a linear interpolation between rows
' of data in a table. The "Entry" value is located in the first
' column of the table, then an appropriate value from another column
' in the table (specified by "Col") is interpolated and returned.
' The value of "Col" must be equal to or greater than 2, and less
' than the total number of columns in the table.
' If "Entry" is outside the defined span of the first column
' the function returns #VALUE.
' Note that the method used requires that the first column
' contains values that either increase or decrease monotonically.
' It this condition isn't satisfied the function returns #VALUE
'
Dim NR, NC, i As Integer
'
NR = Table.Rows.Count
NC = Table.Columns.Count
If NR < 2 Or NC < 2 Or Col < 2 Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If NC < Col Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If Table(1, 1) < Table(NR, 1) Then
i = 2
Do While i <= NR
If Table(i, 1) < Table(i - 1, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
i = i + 1
Loop
If Entry < Table(1, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If Entry = Table(1, 1) Then
VLin_Interp = Table(1, Col)
Exit Function
End If
If Entry > Table(NR, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If Entry = Table(NR, 1) Then
VLin_Interp = Table(NR, Col)
Exit Function
End If
End If
If Table(1, 1) > Table(NR, 1) Then
i = 2
Do While i <= NR
If Table(i, 1) > Table(i - 1, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
i = i + 1
Loop
If Entry > Table(1, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If Entry = Table(1, 1) Then
VLin_Interp = Table(1, Col)
Exit Function
End If
If Entry < Table(NR, 1) Then
VLin_Interp = [#VALUE!]
Exit Function
End If
If Entry = Table(NR, 1) Then
VLin_Interp = Table(NR, Col)
Exit Function
End If
End If
i = 2
If Table(1, 1) < Table(NR, 1) Then
Do While Entry > Table(i, 1)
i = i + 1
Loop
Else
Do While Entry < Table(i, 1)
i = i + 1
Loop
End If
VLin_Interp = Table(i - 1, Col) + _
(Table(i, Col) - Table(i - 1, Col)) * _
(Entry - Table(i - 1, 1)) / _
(Table(i, 1) - Table(i - 1, 1))
Exit Function
VLin_Interp = [#NUM!]
End Function
```