You can write Disassembler for BizTalk receive pipeline to receive excel file and write the code to read excel data. I am not sure whether there are other ways than using excel oledb component. If you want to follow this way, you need to make some logic to link your excel file to OLEDG datasource (probably another replica of excel file). However this is really difficult to maintain in case of concurrency.
PS: There is one solution to receive/send excel in BizTalk but you will need to pay for this. click here to see, also you can download the trial version if you feel okay.. I am not sure how it works internally though.
Another alternative is to create some services (windows service) to convert .xls file to .csv or directly xml and drop into the biztalk receive location.
Or If it is possible to receive csv files/text file/xml file directly, this is the great way in my view.