If you create a jpg (within and external program) representing the transparent within your object and then upload it into the Alpha channel using the "Map" option it will then complete the transparency required. However... it is advisable to learn about UVmapping other wise you may not get the effect you wish for. You have to realise also that a tranparency map and texture map are exactly the same, just a jpg or similar image format that offers the transparency range using a variation of tones between black and white.