  We report sensitive imaging observations of the CO J=1-0 line emission in the
powerful high-redshift radio galaxy 4C 41.17 (z=3.8) with the NRAO Very Large
Array (VLA), conducted in order to detect the large concomitant H_2 gas
reservoir recently unveiled in this system by De Breuck et al (2005) via the
emission of the high excitation J=4-3 line. Our observations fail to detect the
J=1-0 line but yield sensitive lower limits on the R_43=(4-3)/(1-0) brightness
temperature ratio of R_43 ~ 0.55 - >1.0 for the bulk of the H_2 gas mass. Such
high ratios are typical of the high-excitation molecular gas phase ``fueling''
the star formation in local starbursts, but quite unlike these objects, much of
the molecular gas in 4C 41.17 seems to be in such a state, and thus
participating in the observed starburst episode. The widely observed and unique
association of highly excited molecular gas with star forming sites allows CO
line emission with large (high-J)/(low-J) intensity ratios to serve as an
excellent ``marker'' of the spatial distribution of star formation in distant
dust-obscured starbursts, unaffected by extinction.
