Lanter Reporting Site - repost

need design a site that will allow our company to post an excel spreadsheet that will allow up to 15 users to sign in simultaneously and modify these excel sheets as needed [login to view URL] reports would be viewed by our local customer service reps daily for generating reports to our customers with the data that they contain that was put in by the end users. site needs to allow approx 4 different reports to be housed on it for daily modifing and viewing by multiple users at one time