no variable of this type %xxxx% can not be added or changed because it is part of the source code, you can use against personal variables macro type using the data available as {.^user.} and {.^email.}
for that you must put them in the existing section [Special: alias] located in the template.
[special:alias]
check session=if|{.{.cookie|HFS_SID_.} != {.postvar|token.}.}|{:{.cookie|HFS_SID_|value=|expires=-1.}
{.break|result=bad session}:}
can mkdir=and|{.get|can upload.}|{.!option.newfolder.}
can comment=and|{.get|can upload.}|{.!option.comment.}
can rename=and|{.get|can delete.}|{.!option.rename.}
can change pwd=member of|can change password
can move=or|1|1
escape attr=replace|"|"|$1
commentNL=if|{.pos|<br|$1.}|$1|{.replace|{.chr|10.}|<br />|$1.}
add bytes=switch|{.cut|-1||$1.}|,|0,1,2,3,4,5,6,7,8,9|$1 Bytes|K,M,G,T|$1Bytes
email=%user%
user=substring||@|%user%
each new account must necessarily be registered with the email address, which be used to identify the login of form name@domain
which can not be changed is the value of %user%=name@domain, at each location of the template, where a comparison with %user% is necessary for the protection of data, it will change nothing.
By cons, to various places will appear or used email or user name (that of the email) then we can put respectively {.^email.} and {.^user.}.
that's all it is physically possible to the email adrese should serve as an identifier for the connection, and then transmitted as a form for registration be stored separately in a table of HFS type of external file for use in subsequent spots
[special:alias]
......
email=from table|{.load|D:\HFS\emails.txt.}|%user%
user=%user%
example of emails.txt containing lines as user=name@domain
SonyUSA=Censorius.Hybernatus@gmail.org
root=root@mydomain.com
.....