What do you mean by only counting a specific row, a specific row is always going to have 0 or 1 occurances. Do you mean column? Well in that case you'll always have as many columns as you have records that match your where clause.
For example
SELECT COUNT(*) FROM table_name
will return the same value as
SELECT COUNT(ID) FROM table_name
(as long as ID is a valid field name for this table.
Now maybe you only want records where a specific field has data in it and it not blank then you would do this
SELECT COUNT(*) FROM table_name WHERE field_name != ""
understand?