Program a permanent DTMF sequence before dialup

[Masch]

100 euro REWARD for programming solution !!

I want to program a permanent DTMF sequence before dialup in my Nokia 3310, without making any changes on the simcard.

I'm using this mobile just to call internationally for my business.

I can dialup straight out thru my carrier (0033123456789), but this is very expensive. So I preset a DTMF sequence with a cheaper 0900-carrier for the often dialed numbers in my phonebook (09001234p0033123456789#). For the numbers that are not in my phonebook, I dialup by typing this complete sequence every time.

Is it possible to program a permanent locked DTMF sequence (09001234p) in my mobile, so I could just dial 0033123456789 and my mobile automatically puts the prefixed DTMF sequence in front of the number I want to call ?

Does anyone know how I can fix this ?

The first one who posts me the solution (date/time post decides) gets the reward !