Creating stored procedure that uses CONNECT TO myserver USER myuser USING password fails

I've got an SQL stored procedure I'm trying to create...

CONNECT TO MYSERVER USER MYUSER USING mypass;

I want mypass to be a variable, however I can't get it to work.

I've tried defining mypass as
- a local variable to in the stored proc
- a global variable outside the SP
- a parm to the stored proc.

In all cases, the ILE C compile fails
--local
EXEC SQL CONNECT TO MYSERVER USER MYUSER USING :SQLP_L2.MYPASS ;
* SQL0104 Position 48 Token : was not valid. Valid tokens:
<IDENTIFIER>.
--parm
EXEC SQL CONNECT TO MYSERVER USER MYUSER USING :NMYPROC.MYPASS ;
* SQL0104 Position 48 Token : was not valid. Valid tokens:
<IDENTIFIER>.
--global
EXEC SQL CONNECT TO MYSERVER USER MYUSER USING MYPASS ;
* SQL0104 Position 48 Token MYPASS was not valid. Valid tokens:
:.

According to the doc, CONNECT TO is an executable statement...and it can't
be dynmaically prepared...

So what am I doing wrong?

Thanks!
Charles