Aquí hay un código que puede usar como referencia. Espero eso ayude.
Sub SelectBasic()
Dim objDb_con
Dim strSomeValue As String
Set objDb_con = CreateObject("ADODB.Connection")
Set Rsdatatype = CreateObject("ADODB.RecordSet")
glbConnString = Trim(ActiveSheet.Range("B1").Value)
//Connection string format:Driver={PostgreSQL Unicode};Database=MyDB;server=192.16*.*.**;UID=USERID;Pwd=pasword //comment it
If glbConnString = "" Then
MsgBox "Enter the Connection String"
Else:
objDb_con.Open glbConnString
strSql = "select strSomeValue from SOMETABLE where Something=1"
Rsdatatype.Open strSql, objDb_con, adOpenKeyset, adLockpessimistic
If Rsdatatype.EOF = False Then strSomeValue = Rsdatatype.Fields(0).Value
Rsdatatype.Close
End If
objDb_con.Close
End Sub