asp.net forms authentication wholly username

i have bit hybrid conditions hands. i'm minute an intranet asp.net web app. i don't wish full blown windows authentication, since i don't have repremand groups set adult active office means justify users simply formed organisation in. adult until now, i combined membership database, manually authenticating users formed nt login. app removing some-more complex, i'm looking during controlling membership roles providers justify users. here's issue: i wish means justify users only formed nt, nonetheless i don't wish windows authentication. i wish possess provider block membership roles providers, forms authentication, nonetheless transparent. formed users table, i wish means justify user route formed nt alone. possible, am i stranded minute possess little horizon accomplish this? i take advantage provider horizon during possible.