Import["dir\file",expr,"type"] - see help. certainly you can specify path
If your working with (mouse, and if your using an Apple imac (great machine), If your using Microsoft, the way to do that is to click on the ".." icon or the path tree. this changes the "working directory" you see to select a file from.
Mathematica can cut and paste rows and colums of data from Excel certainly. You may need to "right click" and choose the copy and past format (in excel at least), since mathematica may not support all excel paste formats (pasting intended to be embedded in another excel sheet).
In: $ImportFormats
Out: { list of supported formats }
In: Directory[]
Out: "your current working directory"