  CoRoT-7b, the first transiting ``superearth'' exoplanet, has a radius of 1.7
R_Earth and a mass of 4.8 M_Earth. Ground-based radial velocity measurements
also detected an additional companion with a period of 3.7 days (CoRoT-7c) and
a mass of 8.4 M_Earth. The mass of CoRoT-7b is a crucial parameter for planet
structure models, but is difficult to determine because CoRoT-7 is a modestly
active star and there is at least one additional companion. A Fourier analysis
was performed on spectral data for CoRoT-7 taken with the HARPS spectrograph.
These data include RV measurements, spectral line bisectors, the full width at
half maximum of the cross-correlation function, and Ca II emission. The latter
3 quantities vary due to stellar activity and were used to assess the nature of
the observed RV variations. An analysis of a sub-set of the RV measurements
where multiple observations were made per night was also used to estimate the
RV amplitude from CoRoT-7b that was less sensitive to activity variations. Our
analysis indicates that the 0.85-d and 3.7-d RV signals of CoRoT-7b and
CoRoT-7c are present in the spectral data with a high degree of statistical
significance. We also find evidence for another significant RV signal at 9
days. An analysis of the activity indicator data reveals that this 9-d signal
most likely does not arise from activity, but possibly from an additional
companion. If due to a planetary companion the mass is m = 19.5 M_Earth,
assuming co-planarity with CoRoT-7b. A dynamical study of the three planet
system shows that it is stable over several hundred millions of years. Our
analysis yields a RV amplitude of 5.04 +/- 1.09 m/s for CoRoT-7b which
corresponds to a planet mass of m = 6.9 +/- 1.4 M_Earth. This increased mass
would make the planet CoRoT-7b more Earth-like in its internal structure.
