How to hack portable Strawberry's libpth

Hi,

Having installed a portable build of Strawberry 5.20.0, how do I then alter 
$Config{libpth} - such that the alteration to $Config{libpth} is already in 
place every time I open up an instance of the strawberry shell ?

For my own Windows perls, I would do this by editing appropriately the 
libpth entry in Config_heavy.pl and Config.pm, but Stawberry seems to be 
reading libpth from some other source(s) as the entries in Config_heavy.pl 
and Config.pm don't even match $Config{libpth}.
And changing the libpth entries in those 2 files doesn't seem to be having 
any effect at all.

Cheers,
Rob