Do some Excel Work

Need to do a customize excel sheet or if there is a free software i can use it is [login to view URL] is for a inventory. Need to be able to : - generate a barcode for my products (unique barcode per product ) - create a list with information with a drop down list if it sold or not , company that bought it and who they bought it for. - if they bought it for smith if i click on it name it suppose to send me on another spreadsheet with information about smith like address , cellphone number and so on. I need to have another spreadsheet where i can do search with name, address cellphone any input even with the scanning of the product bar code. i have a mac,a pc and a USB barcode scanner already. I need them to work on both the same way. i need to be able to have instruction to move it to another computer if i need to.