ranas administrator command help

[rakem]

iam trying to automate the install of a backup agent to our users, it has to do it through login scripts. The poblem is that alot of our users are restricted users (windows xp) so they cant install programs, which means that i need to use a runas command in the login script, e.g. runas administrator, however using the runas command it asks for the administrator password in the command promt, which the users do not know, so my question is, is there a way to use the runas command to install the agent and also include the password in the script so that it is fully automatic?