LDAP Filter : works with full value, but not with part_of_value*

[<Maxime.Gheysen@swisscom.com>]

Hello,
I use a filter to filter (of course!) my search to some groups (groups
are attribute). 
If I search :
(memberOf=CN=DG_IT-CLI-DAR_A_00,OU=IT_CLI-DAR,OU=IT_Generic,OU=IT_Res,OU
=IT,DC=corproot,DC=net)
I get all values, but I want also ...DG_IT-CLI-DAR_A_01... and
...DG_IT-CLI-DAR_A_02...

If I filter
(memberOf=CN=DG_IT-CLI-DAR_A_0*,OU=IT_CLI-DAR,OU=IT_Generic,OU=IT_Res,OU
=IT,DC=corproot,DC=net) I get nothing, same with
(memberOf=CN=DG_IT-CLI-DAR_A_0*). 

Why does the wildcard not work? And is there any wildcard for
"any_letter" for just one letter variable?

Thanks