Why I can't move md5 password from ldap to shadow (fwd)

[netadmin <netadmin@nowy.isp.pl>]

Hi...

Sorry but my english is very bad...

I can move password from ldap to shadow but only when they was crypt'ed :
userpassword={crypt}xxxyyyzzz.

I have some password with md5 :
userpassword={md5}12345678901234567890==
but they don't work...
In shadow i shoud have $1$xxyyzzuu$qqwweerrtt...

help...

netadmin@nowy.isp.pl