Honestly I'm not 100% sure what you're trying to ask, feel free to spend a bit more time fleshing out the problem so that we can help you better. However, if you are trying to assign a hair system to curves, I.E. 'Assign system to curves', and it is giving you the error about attaching them to polygons, then you should…
Thank you very much. Oh my god you saved my life twice :D oh i almost forgot... http://www.yurialexander.com/charactersmain/shadows/ did you used plugin in hair? or just maya hair system ? thank you :)