You will need to create a new employee list for monthly payroll for your current semi-monthly employees. Create the sub-folder by selection NewViews > Payroll > Country > and select the Advanced Button > Sub Payrolls > Folder Management. Insert a new for the new monthly payroll and then select Employees > List and add your employees with a new prefix. You can use Tools > Copy Existing Employee Accounts to copy the existing semi-monthly employee layout to your new Monthly sub-folder.
I suggest that you have this done for the first payroll in 2010.
Regards to All,