.txt file is free format. You can notepad your phone.txt like this and separate multiple phone by , (Leading + for global phone #)
9176091234,6102034321,
6463391234,+5511970881234,6469324321,+447849001234,
3522841234,+447527221234,7864731234
notepad your text.txt file like this
This is a sms text for smscmd. It is up to 155 chars, the text will be truncated after 155 chars ............
Second line ..........