Coupon Validation

I am looking for some help on a internal Intranet form for database entry. I currently have an Excel worksheet (macro) that works as follow: A magnetic card swipe inputs customer # into an input text field which dumps it into a column, then a barcoded coupon is scanned and enter into another column in the same manner. The two are then merged into a third column,it combines the two as a unique combination. So, if a customer trys to use the same card # and barcoded coupon again it is rejected as already being redeemed.. There is also a time/date stamp added to each entry in a new column, as well as a machine ID entry into a new column for location where it was redeemed in the store. The current Excel based Coupon validation System also tracks customers who attempt to abuse the system, by popping up a warning message that a coupon has been redeemed, then copying thier card # and coupon code to an "abusers" page in the spreadsheet.. In the final workbook we have a redeemed page, and an abusers page with the following info: CARD#|COUPONBARCODE|CARD#&BARCODECOMBINED|TIMESTAMP|L0CATION| This info is inserted into the redeemed page by an Excel Form, and then is also inserted on to the abuse page in the same format when a duplicate CARD# & BARCODE combination is entered. So when we are harvesting data we get a listing of all coupons redeemed, by date and time and promo barcode. As well as customers who would potentially abuse the system. It seems the same Card#s pop up frequently on the abuse page. It makes it easier for us to identify those problem customers. This does work rather effectively; there are some sharing issues that pop up from time to time. One of the features I would like to add is a validation by time/date stamp and Customer Card ID, so a customer can only redeem one bar-coded coupon per day. If the same acct# is entered on same business day it will popup an error message to the data entry person stating another coupon already redeemed that day. There might be as many as 2-3 valid coupons at any given time. some with an option of a one time use coupon, another for a specific date, another perhaps that can be redeemed only on a weekly basis, or a once a year coupon as in a birthday or anniversary promotion, etc.. The excel system with the card swipe and barcode validation combination has cut down on the amount of abuse by some of the umm? Shadier customers. I am looking on how to convert this to PHP/HTML to dump into a MYSQL Database. I think this would eliminate the sharing issues, plus be easier to query for data harvesting on the back end. I want to eliminate the file sharing issues of excel, and have a friendlier interface for employees to use. I currently have a system running winxp pro with IIS and PhP 4.39 with latest MySql version. Our business day runs differently then the standard calendar day, we use from 7:00am-7:00am as our business day. I can zip all the files I have so far and email them for review to and whom ever is interested. This is meant to be an internal data entry platform only. I am wanting a SUPER version of MS access for data entry with damn near unlimited potential. Thanks for any help in advance, Sam Shinn