This is the amended code:

Option Compare Database
Option Explicit

Dim NICode As String
Dim rs As ADODB.Recordset
Dim cn As ADODB.Connection

Dim strSQL As String

Set cn = Application.CurrentProject.Connection
Set rs = New ADODB.Recordset
NICode = "txtLetter"

strSQL = "SELECT " & NICode & "1a, " & NICode & "1b, " & NICode & "1c, " & NICode & "1d & NICode & "1g & NICode & "1h FROM WorkPlace NI Breakdown"

rs.Open strSQL, cn

If Not (rs.EOF And rs.BOF) Then
   MsgBox rs.Fields(NICode & "1a")
   MsgBox rs.Fields(NICode & "1b")
   MsgBox rs.Fields(NICode & "1c")
   MsgBox rs.Fields(NICode & "1d")
   MsgBox rs.Fields(NICode & "1g")
   MsgBox rs.Fields(NICode & "1h")


End If
rs.Close
cn.Close

Set rs = Nothing
Set cn = Nothing

Alright, we're getting close. A couple of changes (ignore the *'s they just indicate the lines I have changed)

Option Compare Database
Option Explicit

*Private Sub cmdRun_Click()

Dim NICode As String
Dim rs As ADODB.Recordset
Dim cn As ADODB.Connection

Dim strSQL As String

Set cn = Application.CurrentProject.Connection
Set rs = New ADODB.Recordset
NICode = "txtLetter"

*strSQL = "SELECT " & NICode & "1a, " & NICode & "1b, " & NICode & "1c, " & NICode & "1d & NICode & "1g & NICode & "1h FROM [WorkPlace NI Breakdown]"

rs.Open strSQL, cn

If Not (rs.EOF And rs.BOF) Then
   MsgBox rs.Fields(NICode & "1a")
   MsgBox rs.Fields(NICode & "1b")
   MsgBox rs.Fields(NICode & "1c")
   MsgBox rs.Fields(NICode & "1d")
   MsgBox rs.Fields(NICode & "1g")
   MsgBox rs.Fields(NICode & "1h")


End If
rs.Close
cn.Close

Set rs = Nothing
Set cn = Nothing

*End Sub

Mike
EchoVue.com

That has cleared the compile error. I am now receiving an error: Run Time Error '13' Type Mismatch. Which refers to line:

Set cn = Application.CurrentProject.Connection