To connect to Excel sheets with exMon you need to install Microsoft Access Database Engine 2016 Redistributable on the exMon machine.

1. Download ACE driver: and install on the exMon machine. In almost every case you need the 64 bit driver.

2. Create a new Data Provider in exMon, select Excel as the data provider type and for Connection String put:

    Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\PATH\TO\MY\Book1.xlsx;Extended Properties="Excel 12.0;HDR=YES"

Make sure to have a full path to your Excel sheet and note that you can refer to network paths if the exMon user has enough privileges.

3. Create a Query or Compare Query in exMon and select the newly created data provider.

4. Start by setting the query as 

    SELECT *  FROM [Sheet1$]

 where Sheet1 is the name of your sheet in Excel