RSA crypto - question

hi guys,

 i am new in the list; let me do a  question about GNU Crypto:

 in practice, data is never encrypted directly with RSA. rather the
 data is  encrypted with a random secret key and a symmetric algorithm first,  and the  secret key is encrypted with the RSA key.

 so, the first part is easy, e.g., i can use ICM in order to generate a
 random secret key for AES, and then making an AES encryption of the
 plain text.

 QUESTION IS: how to encrypt the key with RSA ?
 i can`t found out RSA encryption in gnu crypto :-(

 by the way, i wonder if gnu crypto is complaint with the PKCS#1 standard?

 thanks in advance,