Now the calling part has been sorted the good old texting issue.
It is possible to send a text message to an orangeDR phone from the UK, unfortunately it is hit and miss, It is not possible from (for definate) O2 or Virgin mobiles, Vodafone is trial and error normally as is orangeUK. The code if you wish to trial this from the uk is either +1809xxxxxxx or 001809xxxxxxx
When I worked at orange in the DR I made many enquiries as to why it was so difficult (near impossible) to send messages to the DR and nobody knew
to send to the uk is easy use +44xxxxxxxxxx and to call 01144 no '0' from the area code and then the rest of the number.