Qurey in select statment

Hi ,

How can i use select qurey using where clause with 9*....

Example :

SELECT matnr FROM mara into it_mara

WHERE matnr = p_material number.

ie , This is parameter in selection screen -here defaultly giving as below

p_material number = '9*'.

i have used the above select but it failed .can any one help me sort out this ?

Regards

Maha