(DH) how to send dh->pub_key to peer

[ikuzar]

Hello,
I 'd like to know how to send dh->pub_key to peer ?
I know that to send const DH* const_dh, I have to convert it into pem format
like this i2d_DHparams(const_dh, &dhbuf);, then I send dhbuf.
But to send only dh->pub_key, I did not find any function to convert it into
PEM ...
Thanks for your help.