MySQL queries in SQL-Server? How can we best use our existing MySQL queries with SQLserver?

Alternately, what type of changes do we need when we are converting our database server from MySQL to SQLServer?
If it is porting that you are refering to then...MySQL uses a different flavour of SQL compared to Microsoft SQL Server which uses T-SQL (TransactSQL)

There are guides out there if you search that will show you there difference in syntax and perhaps even convert blocks of SQL for you.