Tables, loops and functions

Hi,

In order to append data to a internal table in BRFplus, the only way to do it is with a formula? And with a rule assigning data to a context?

How can I retrieve the line currently executing inside a loop (like sy-tabix)?

In a function I can set as a top expression a rule, but a rule is not a expression. Can I execute as a top expression a rule in BRFplus or is this a bug? Apart from a loop, and if I can't call a rule from a function, how can I call a rule in BRFplus?

Finally, is there any way to call a function with a name and not with the ID of the function (like smartforms in SAP) from SAP?

Thanks.