Well you can get the full command used with something like:
OnNavigate:
.@cmd$ = implode(.@atcmd_parameters$, " ");
if (isloggedin(getcharid(3, .@cmd$)) != 1) {
message strcharinfo(0), "Target player '" + .@cmd$ + "' is offline or do not exist.";
}
sleep2 1;
unitwalkto getcharid(3), getcharid(3, .@cmd$);
end;
Though, unitwalkto is very limited and will most likely fail in most scenarios.