Foreign Nat'l Tax software

Is anyone using a foreign national tax software that is compatible/interfaceable with Lawson?  We are using Windstar which seems to be lots of hand holding of data that already exists in Lawson.  Or does Lawson have a parternship with a software that helpds manage foreign national taxes/exemptions based on treaties. 

Please let me know.  If you have any information, it would be great!