yup it should. You can just try giving row1.alphabet. If that doesn't work, then you can explicitly get the value by using the get method,
(string)globalMap.get("row1.alphabet").
Also your syntax seems a bit off.
It should be where row1.names like '"+(string)globalMap.get("row1.alphabet")+"%'" i.e make sure your double quotes and single quotes are properly enclosed.