Sql Update Command With Variable As ColName

Hello All

 I m trying to update a table whose col name will be read from another table.

For e.g. Table1 gives the result:

'emp1',   1,   'John'

'emp2',   2,   'Mike'

Now in the second table, i need to update the table with Col name  = 'Emp1' and then from the second row (above), I need to update Col name= 'Emp2'

I need to write one Update Statement which will handle all the cases. I tried

Update Table2 set @VariableName = .......

but didnt work...

How can i do that ?