  We describe a theoretical proposal of a nanofibre-based trap for a Rb$_2$
molecule prepared in the metastable state $(1)^3\Sigma^+_u$. The trapping
potential results from the combination of a travelling and a standing-wave
fields, both carried by the fundamental guided mode HE$_{11}$ of the fibre. We
show that, with an experimentally realistic choice of laser frequencies and
powers, one can implement a $\approx 200$ $\mu$K-deep well at $\approx 140$ nm
from the fibre surface accomodating for $\approx 500$ translational molecular
states.
