I'm not entirely sure if I know what you're looking for, but here's a list of freeware/mostly shareware music notation programs you can download:
http://www.freedownloadmanager.org/downloads/music_notation_software_software/The program that I use (MuseScore) is listed on there, and you can download it at
http://musescore.org/en/download. Make sure you read the requirements if you download it, though, since the program takes up 125 MB of space. What you can do is pick what notes you want (8th notes, quarter notes, half notes, etc.) and place it wherever you want on the staff, which is what I think you wanted.
Also
http://musettemusic.com is another program that does the same basic things, and it's takes a lot less space (it's 1.77 MB on my computer), so I would actually try this program out first.
This post was edited by sientran on Jul 25 2009 12:53am