ADO Select Distinct Multiple Columns

I am using ADO to select data from a CSV file, column 1 has some duplicate Incident numbers, but the rest of the columns the data may be different but not interested in that so I cannot use SELECT DISTINCT incident, desciption as this applies to all columns

so I tried the following

StrSQL = "SELECT DT.IncidentNumber, ST.Description -
FROM (SELECT DISTINCT IncidentNumber FROM " & StrFile & " ) DT -
INNER JOIN " & StrFile & " ST ON DT.IncidentNumber = ST.IncidentNumber"

however it returns ALL rows, if I use just

SELECT DISTINCT IncidentNumber FROM " & StrFile

I get the rows I am interested in but not the extra data I require