phrases-what is the template engine?

[MamboCube]

i have required global.php and the phrases work when i use

<?php echo "$bbuserinfo[username]" ;?>

but i want to use the phrase tags so that i can use values from forms (database) for example

<phrase 1="$bbuserinfo[username]">$vbphrase[welcome_x]</phrase>

but when i use phrase tags i just get $vbphrase[welcome_x] as text

i tried making a custom phrase but i cant get it to work with php variables

does anyone know how to either use the phrase tags or to include php variables in custom phrases (if its even possible)

??