INSERT INTO table (field)
SELECT '1stString.' + cast(id as varchar(50)) + '.2ndString'
FROM table2
WHERE id = 10
Edit – response to comment:
You’re on the right track, but you want to select your hard-coded strings from your table, like this:
INSERT INTO table1 (field1, field2, field3)
SELECT '1stVal', '2ndVal', '1stString.' + cast(id as varchar(50)) + '.2ndString'
FROM table2
WHERE id = 10
This is also illustrated in Dustin Laine’s answer.