CCSID quandry

Folks:

I've got another CCSID problem.

On a system that is set to default CCSID 277 ...

One CL program is calling another ... with a 'variant' character in the
parameter.

For example:

Program a: call pgm(b) parm('#ABCDEF')

Program b: pgm (&parm1)
                dcl &parm1 *char (10)
                
                if (&parm1 *eq '#ABCDEF') then(do) /* something */

The problem is, when program B gets control, and does the comparison,
parm1's value doesn't match the constant.

Obviously the programs were written (and tested) with CCSID 37, where
'#' is a valid character.

My question is: Why don't the two constants in the two programs match
when running under CCSID 37?

Thanks!

david