This is, in my opinion a pretty big limitation in RMS. You will need to do both a SelectCustomer and then a SetCustomer to the one selected. You can do this with javascript within an HTML file attached to a custom button. Once you do that you will see a BUG in RMS that causes the screen to not refresh properly.
This drove me crazy for about a year. I have a solution that works around the BUG and I have included the code for the custom button below.
It will probably be unreadable as I post it in this group, but do your best to pick out the code. Copy it to a file and call it getCustomer.html, put the file in your "Store Operations" HTML directory, then attach it to a custom POS button and make the style "HTML Window".
It is a hack, but it works. If anyone has a better solution, please post it.
Regards, Steve P.
Taskpad
Any Info you like can be put here.