The Future is correct -- you cannot create a variable from the contents of a string. However, you can use a hash table to do essentially exactly what you're asking for. It would work, but it's not really the best design strategy. Conceptually, all your "variables" would be stored as a collection. So, your variable names, which are the contents of a string, are the keys. The values are the actual variable values. Each "variable" would be referenced from the hash table (the collection), using the appropriate key.
It can be done, but it's definitely not the best route to take. If you find yourself needing to do this, the best option is to redesign your code, as this is more trouble than it's worth.