Anti-C, anti-e auto-antibody or mimicking antibody
Most warm auto-antibodies have a specificity within the Rh Blood Group System, although some others, more rarely, have a specificity outside of this system, such as auto-anti-Wrb.
Most of the auto-antibodies from within the Rh Blood Group System mimic anti-e, anti-E, anti-C, anti-c or a combination (or even a compound antibody, such as anti-Ce or anti-Rh7), but, in reality, they are actually weak forms of anti-Rh17 and/or anti-Rh18, although strong examples are not unknown). As they are usually mimicking antibodies, they can usually be adsorbed out with red cells that do not actually express the actual antigen on their surface (for example, an apparent anti-e can be adsorbed out using R2R2 red cells).
PLEASE DO NOT try to identify them yourself, as the actual specificity is not significant, but will take an awful lot of time and you will require some VERY rare red cells, such as Rhnull, D--/D-- and the like, and these should be reserved for when they are required to identify the specificity of rare allo-antibodies, such as anti-Hr, anti-HrB or anti-Rh29, where a true specificity may well be vital to identify.
In contrast, most "cold" auto-antibodies are true specificities.
For more information, you would find it hard to beat reading, Petz LD and Garratty G. Immune Hemolytic Anemias, 2nd edition, Churchill-Livingstone, 2004, although I would advise you to be selective, as it is a very detailed book!