find file in directory, copy and paste worksheet

i would like to create a macro to allow users to find the appropriate file in the directory, copy the worksheet and paste it into the worksheet where the macro was clicked.

the file users select will only ever contain one worksheet.

i found the attached macro yet as it lists all files in the directory, i would like to modify it as follows:
1. only show .xls files.
2. copy the found file worksheet and paste it into the worksheet.

thanks in advance