Assistance req translating VBA into SQL User Defined Function

Public Function revconv_ConvA2N(ByVal strInput As String) As Integer
On Error GoTo Err_revconv_ConvA2N

  Dim lLen As Long
  Dim intN As Integer
  Dim intR As Integer

  lLen = Len(strInput)

  If IsNumeric(strInput) Then
    If (lLen = 1) Or (lLen = 2) Then
      revconv_ConvA2N = Int(strInput)
    Else
      revconv_ConvA2N = -1
    End If
  Else
    Select Case lLen
      Case 0
        revconv_ConvA2N = -1
      Case 1
        revconv_ConvA2N = 99 + (Asc(strInput) - 64)
      Case 2
        intN = 26 * (Asc(Mid(strInput, 1, 1)) - 64)
        intR = Asc(Mid(strInput, 2, 1)) - 64
        revconv_ConvA2N = 99 + (Int(Trim(Str(intN + intR))))
      Case Else
        revconv_ConvA2N = -1
    End Select
  End If

Exit_revconv_ConvA2N:
  Exit Function

Err_revconv_ConvA2N:
  Call errorhandler_MsgBox("Module: modshared_revconv, Function: revconv_ConvA2N()")
  revconv_ConvA2N = 0
  Resume Exit_revconv_ConvA2N

End Function

-- Define name of USER-DEFINED FUNCTION for this script
:setvar UDFNAME frevconv_ConvA2N
USE [Fandango]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- Check if the USER-DEFINED FUNCTION exists already, DROP if found
IF EXISTS(SELECT * FROM [sys].[objects] WHERE [type_desc] = 'SQL_SCALAR_FUNCTION' AND [name] = '$(UDFNAME)')
  DROP FUNCTION [dbo].[$(UDFNAME)]
GO
CREATE FUNCTION [dbo].[$(UDFNAME)] (
  -- Add the parameters for the user-defined function here
  @strInput AS varchar(2)
  )
RETURNS smallint
AS
BEGIN
-- Insert statements for user-defined function here
  DECLARE @intLen integer
  DECLARE @sintN smallint
  DECLARE @sintR smallint

  @intLen = Len(@strInput)

  IF IsNumeric(@strInput) THEN
    IF (@intLen = 1) Or (@intLen = 2) THEN
      RETURN = SmallInt(@strInput)
    ELSE
      RETURN = -1
    END IF
  ELSE
    @intLen = Len(@strInput)
  
    SELECT CASE @intLen
      CASE 0
        RETURN = -1
      CASE 1
        RETURN = 99 + (Asc(@strInput) - 64)
      CASE 2
        intN = 26 * (Asc(Substring(@strInput, 1, 1)) - 64)
        intR = Asc(Substring(@strInput, 2, 1)) - 64
        RETURN = 99 + (SmallInt(fTRIM(Str(intN + intR))))
      CASE ELSE
        RETURN = -1
    END SELECT
  END IF

END

-- Define name of USER-DEFINED FUNCTION for this script
:setvar UDFNAME frevconv_ConvA2N
USE [Fandango]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- Check if the USER-DEFINED FUNCTION exists already, DROP if found
IF EXISTS(SELECT * FROM [sys].[objects] WHERE [type_desc] = 'SQL_SCALAR_FUNCTION' AND [name] = '$(UDFNAME)')
  DROP FUNCTION [dbo].[$(UDFNAME)]
GO
CREATE FUNCTION [dbo].[$(UDFNAME)] (
  -- Add the parameters for the user-defined function here
  @strInput AS varchar(2)
  )
RETURNS smallint
AS
BEGIN
-- Insert statements for user-defined function here
  DECLARE @intLen integer
  DECLARE @sintN smallint
  DECLARE @sintR smallint
  DECLARE @sintRC smallint

  SET @intLen = Len(@strInput)

  IF ISNUMERIC(@strInput) = 1
    IF (@intLen = 1) Or (@intLen = 2)
      SET @sintRC = CONVERT(smallint, @strInput)
    ELSE
      SET @sintRC = -1
  ELSE
    BEGIN
      IF @intLen = 0
          SET @sintRC = -1
      ELSE IF @intLen = 1
          SET @sintRC = 99 + (ASCII(@strInput) - 64)
      ELSE IF @intLen = 2
        BEGIN
          SET @sintN = 26 * (ASCII(Substring(@strInput, 1, 1)) - 64)
          SET @sintR = ASCII(Substring(@strInput, 2, 1)) - 64
          SET @sintRC = 99 + (CONVERT(smallint, dbo.fTRIM(STR(@sintN + @sintR))))
        END
      ELSE
        SET @sintRC = -1
    END
[COLOR=Red]RETURN @sintRC[/COLOR]

Msg 102, Level 15, State 1, Procedure frevconv_ConvA2N, Line 36
Incorrect syntax near '@sintRC'.