can't do it as cannot find the + sign to put before the country code, without which it will not send, where is it?

Press and Hold Down the "0" key

//Edit: Most keypads have it on the '0' (zero) key, but some may have the option under the '1' or '*" key.

On a Microsoft website, they write this:

Where's the 'plus' sign?

When the keyboard's up, tap "&123" to open the symbol keyboard. The "&123" button will change to a "abcd" button. Just above that button is an arrow pointing right (where Shift used to be). Tap the arrow and it'll point left, and bring up more symbols where you'll find the + sign among other math and extra symbols.

I'm so glad I don't own a Nokia/Microsoft phone.

Thanks for that, very helpful

On some phones, i've found that it is a long "0" press. On my Skype handset, it is a double"00" press.