plpgsql - accessing fields of record type

Hi!

I'd like to ask whether it is possible to access fields of record type 
variable in plpgsql in the following way:

I have a table with field named "XY_1", "XY_2", ... "XY_255".
I want to access the values in the table from a plpgsql function somehow 
in a loop with the iterative variable. Can I address the appropriate   
''XY_'' || loopvariable    field with the help of the loop variable?
If I can, what is the syntax of this? Sorry, I've read through the 
documentation, but haven't find any solution.

I have thought of an alternative solution: can plpgsql convert a record 
type into array? (Then I could address the field value with the nth 
element of the array)

Thanks for your help

tomasz