Sorry, i see this question has been posted and answered before. Hope the velocity option will be added soon!

theres a free plugin called "midivelocityscale Insert Piz here". you put it before the instrument youre triggering in the plugin chain, and it lets you adjust how velocity will be handled. for example, when im playing samples taken from the same song and i dont want the noise floor going up and down, i set the velocity to 127 and no matter how hard i press the key, it all comes through at the same level. or you can set it to 100-127 and get small differences in volume like when youre playing single hit drums.

Thanks (a little late;-) for your reply! It seems like this plugin is not available anymore, it's not listed on the Insert Piz Here website.