ORA-01461 - When inserting pound sign

Wonder if anyone can help with this issue?

I'm running Oracle Forms [32 Bit] Version 10.1.2.0.2 (Production) with OC4J 10.1.2.0.2 against Oracle database version 11.1.0.7.0. where the NLS_CHARACTERSET on the database is AL32UTF8.
NLS_LANG on my machine is:

 SQL> @.[%NLS_LANG%].
 SP2-0310: unable to open file ".[AMERICAN_AMERICA.WE8MSWIN1252]..sql"
 SQL>

I have a form with a non database block containing a push button and text item field, Data Type - CHAR, Maximum Length - 1000, Data Length Semantics - Null

create table amc_pound_test
( apt_id    number
, text1   varchar(2000)
)
;

Using the button with a When-Button-Pressed trigger I try to insert the text, "£1", into the above table using the following code: