The USERLID or USERXLID section (each section is 192(DECIMAL), C0(HEX) BYTES, so a total of 384 180(hex) bytes) of the LIDREC DSECT can be used to include the new @CFDE fields in the logonid record.
First, you will need to figure out how much space is left to add user defined fields.
Depending on how much space is left in your configuration, here is a sample example to add 6 user defined fields 64 bytes in length. The two changes need to be made for USERLID and CFDE entry as shown below:
USERFLD1 DS CL64
USERFLD2 DS CL64
USERFLD6 DS CL64
To implement the changes mentioned above, follow this KD article which explains the process to make these changes using USERMOD UM99901.
If you are running out of space, the other option is to define the user profile records in infostorage database. The procedure is described here.