I'm a little bored, so I put together a quick excel UDF in VBA that would do what you need.

This was done quickly, so there is probably a better way to do some of it, but it works. It also assumes the input and output of the SQL scalar function are integers

Public Function SQL_UDF(intInput As Integer) As Integer

Dim cnt As ADODB.Connection

Dim rst As ADODB.Recordset

Dim cmd As ADODB.Command

Dim stCon As String 'SQL Connection string

Dim stQuery As String 'Query string

'Set ADODB requirements

Set cnt = New ADODB.Connection

Set rst = New ADODB.Recordset

Set cmd = New ADODB.Command

'Define database connection string

stCon = "Provider=SQLOLEDB.1;"

stCon = stCon + "Integrated Security=SSPI;"

stCon = stCon + "Persist Security Info=True;"

stCon = stCon + "Data Source=SQLSERVER;"

stCon = stCon + "Initial Catalog=TestDB"

'Open database connection

cnt.ConnectionString = stCon

cnt.Open

' Defines the stored procedure commands

stQuery = "select dbo.TestFunction(" & intInput & ")" 'Define name of Stored Procedure to execute.

'cmd.CommandType = adCmdStoredProc 'Define the ADODB command

cmd.CommandType = adCmdText

cmd.ActiveConnection = cnt 'Set the command connection string

cmd.CommandText = stQuery 'Define Stored Procedure to run

'Execute query and return to a recordset

rst.Open cmd.Execute

SQL_UDF = rst.Fields(0).Value

'Close database connection and clean up

If CBool(rst.State And adStateOpen) = True Then rst.Close

Set rst = Nothing

If CBool(cnt.State And adStateOpen) = True Then cnt.Close

Set cnt = Nothing

End Function