Custom PD Infotype for TEM

Hi,

I need to create a custom infotype in TEM to capture course credits.

I am using tcode PPCI as my starting point. But unable to start the creation since I am getting a message that the structure HRInnnn does not exist.

Can someone tell me how to create this sructure?

Or has a step by step document on creating a custom PD infotype in ECC 6.0?

Please help.

Thanks.