SHELL variable causing /c: error message on NT

[bzelitch]

I am using Windows 2000. I am trying to set the 
SHELL variable to bash. This makefile produces 
the error message which follows:

***makefile***
SHELL=/usr/bin/bash
all:
        echo ${SHELL}

***error message***
/c: /c: No such file or directory

I have also tried 1) setting SHELL as
SHELL=C:/cygwin/bin/bash.exe
and 2) setting SHELL as an exported environmental 
variable.

Any help with what I should be doing would be 
appreciated.

Thanks!