Embedded SQL examples

Hi there,

I'm trying to write an UPDATE statement within a COBOL program where the 
Filename as well as the values to update are all parameterised.

I can get the FILENAME to work if I use the PREPARE statement but not the 
values - and I can get the values to work in a straightforward UPDATE but the 
FILENAME is then not allowed as a parameter.

I had imagined I may be able to construct something like this:

EXEC-SQL
    UPDATE    :FILENAME
        SET     :FIELDNAME1    TO    :VALUE1
            WHERE     :FIELDNAME2    =    :VALUE2
END-EXEC  

If I string it altogether as a prepared statement the resulting command does 
not execute from within the program as it assumes the values to be a fieldname 
but if I copy and paste the same command into STRSQL it works fine - so what am 
I doing wrong?

Anyone got some examples that work??

Many Thanks,

Chris