What you are looking for is called Active Data
in Silk Test.
It allows enhancing your visual tests with external data, for example from an Excel file.
ActiveData testing enables you to leverage existing data in external files as input for powerful, comprehensive application testing solutions. ActiveData testing enables you to perform multiple transactions against test applications using a different set of data for each transaction without writing complicated code or compromising existing data.
You can find an introduction to Active Data in the online documentation or in the tutorial video.