passing numbers to go scripts (probably dumb syntax question)

[Peter Rayner <pjr@xxxxxxxxxxxxxxxxxxxxxxxx>]

I would like to do something like
yes? repeat/k=1:14 go runmask k
and in runmask have something like
yes? let temp = mask[k=k]
yes? let maskflux = temp * flux
...
where flux and mask have the same lat-lon grid and flux is also a
function of time
this is to produce integrals over  defined but irregular regions
stored in mask, mask is defined as multi-level and we loop over
levels.  
the mask[k=k] seems to cause a problem like
 **ERROR: command syntax: K
while just
yes? go runmask 1
causes no problem.
This suggests I'm misunderstanding how to pass a number rather than  a
string through to a go script or at least that's what it sounds like..
Very likely this is a dumb piece of syntax on my part but I confess
I'm not seeing it ... any pointers gratefully received.
Peter Rayner