Convert number to words

Content

Hi,

In the invoice report which has payment terms of 10 months it generates 10 invoices with payment due date, amount and the instalment  number say 1...10

The instalment sequence is stored as number in database

In the RTF template if the how can I print the instalment user say it is 

1 to be shown in output as First, 2 --> Second, 3 --> Third

Attached screenshot for reference

Thanks