I need to test a string of text that needs to contain a certain type of char values. The known is allowing of a-z,A-Z,0-9. But the variable (which will be coming from a database field) will be the allowed symbols. The allowed symbols will look something like:

!@#$%^&*()

So using regex, how can I check a string of text to make sure it ONLY contains a-z,A-Z,0-9 AND the allowed symbols as shown above? Remember, the allowed symbols is dynamic at run time so I need to somehow be able to plug that in to the method at run time.

The following examples would be valid using the above symbol string:

Test1234%
Test1234

The following example would NOT be valid:

Test1234%_