How to create a Quotaion form in Excel to use in touch screen PDAs

I need to design an Excel spreadsheet Quotation Form to use in touch screen PDAs to prepare quotations for customers for a carpet store. Due to PDA it should be thin and be able to use drop down menu to select type of carpets, price, and buttons to give discounts. Also needs to add extras such as underlay, gripper strip and fittings. Due to touch screen PDAs minimal typing is the aim to ease the process.
Thanks for all your expert advice.