How to find a string within a string in sqlite?

[buiduytan]

ex:
I have a string with value "#1#2#3#" in A column, and my input value is "#2#". How to find it in A column? in MySQL, I can use Regexp function to string comparison, but in Sqlite, I dont know how to do it? can not use LIKE because my input value can be "#3#2#".
pls show me the solution, thank you!