Hi there,

I don't have ready-made VB.NET code for you, but here are some examples
using native Visual Basic:

http://msdn2.microsoft.com/en-us/library/aa705921.aspx

If you can get the property "userAccountControl" of your user object, then
you should be able to change the settings you are after. The value is a flag
value, and here are (in C#) the possible flag values:

public enum ADS_UF_ENUM
{
ADS_UF_SCRIPT = 0X0001,
ADS_UF_ACCOUNTDISABLE = 0X0002,
ADS_UF_HOMEDIR_REQUIRED = 0X0008,
ADS_UF_LOCKOUT = 0X0010,
ADS_UF_PASSWD_NOTREQD = 0X0020,
ADS_UF_PASSWD_CANT_CHANGE = 0X0040,
ADS_UF_ENCRYPTED_TEXT_PASSWORD_ALLOWED = 0X0080,
ADS_UF_TEMP_DUPLICATE_ACCOUNT = 0X0100,
ADS_UF_NORMAL_ACCOUNT = 0X0200,
ADS_UF_INTERDOMAIN_TRUST_ACCOUNT = 0X0800,
ADS_UF_WORKSTATION_TRUST_ACCOUNT = 0X1000,
ADS_UF_SERVER_TRUST_ACCOUNT = 0X2000,
ADS_UF_DONT_EXPIRE_PASSWD = 0X10000,
ADS_UF_MNS_LOGON_ACCOUNT = 0X20000,
ADS_UF_SMARTCARD_REQUIRED = 0X40000,
ADS_UF_TRUSTED_FOR_DELEGATION = 0X80000,
ADS_UF_NOT_DELEGATED = 0X100000,
ADS_UF_USE_DES_KEY_ONLY = 0x200000,
ADS_UF_DONT_REQUIRE_PREAUTH = 0x400000,
ADS_UF_PASSWORD_EXPIRED = 0x800000,
ADS_UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION = 0x1000000
};

From these flags, the values ADS_UF_PASSWD_CANT_CHANGE and
ADS_UF_DONT_EXPIRE_PASSWD should be the ones you need. Haven't tested,
though.

Hope this helps!