Here's the problem with which you're faced in doing so. Most vegetables sold in stores are hybrids that are developed for some very specific qualities, such as storageability, color, skin thickness and others. This means the cucumber you buy in the store was produced from two parents and will produce that particular vegetable for one generation only . You may not, no, probably won't, get the same cucumber as you'd hoped. Additionally, some seeds from some plants don't pollinate very well due to their hybrid characteristics. You'd be much better off and a lot less likely to be dissapointed by buying a good quality fresh seed packet from a reputable garden supply store... in my opinion... Good growing!