One way to do the comparison would be to import the Excel data into a new table in your Access database file. Then you could run queries in Access comparing the records in the two tables. Once you are finished with the new table, with the imported Excel data, the table can be deleted.
If the sheet in the Excel file doesn't have column headings in the first row then copy the data onto a new sheet and insert column headings into the first row. This might be easier than assigning column headings one field at a time during the import process. I usually avoid spaces in the column headings that will be used for field names. Access will offer to add a key field and I usually let it...shouldn't matter either way. When you do the import make sure to select the correct sheet in Excel.
Importing data from Excel into Access is easy and it should only take a few minutes. I hope this helps.