  We present an improved method of targeting continuous gravitational-wave
signals in data from the LIGO and Virgo detectors with a higher efficiency than
the time-domain Bayesian pipeline used in many previous searches. Our spectral
interpolation algorithm, SplInter, removes the intrinsic phase evolution of the
signal from source rotation and relative detector motion. We do this in the
frequency domain and generate a time series containing only variations in the
signal due to the antenna pattern. Although less flexible than the classic
heterodyne approach, SplInter allows for rapid analysis of putative signals
from isolated (and some binary) pulsars, and efficient follow-up searches for
candidate signals generated by other search methods. The computational saving
over the heterodyne approach can be many orders of magnitude, up to a factor of
around fifty thousand in some cases, with a minimal impact on overall
sensitivity for most targets.
