Automatically adding text in front of a string


We are collecting phone numbers for our clients -- was wondering how to best go about automatically adding country code to a number?

For example: User with input 9-digit number (xxxxxxxxx) and invisible variable would automatically add '+xxx' (country code) in front of the number. Can anyone help with that?

Thanks for your help!


Just add a hidden value afterwards, and concatenate the country code onto the front, then use that calculated value as your phone number for sms's etc. Eg for the hidden value: concat("01", #form/question with 9 digits)