Formula to return contents of a cell using file path and cell coordinates

Is there a formula to look up an excel file with the file pathway, sheet name, and cell number?

For example, return the contents of cell G55 on Sheet1 in file path P:\Stuff\CUSTOMERS\Customer1\ExcelFile.xlsm.

The other thing is I put the file path in a cell. In the example above, the file path is in cell P2. So the formula would have to read in cell P2 (the file path), then the sheet name, then the cell and return whatever is in that cell.

I've tried INDIRECT.EXT and also direct links using "=", but it always asks me to give it the path again, even after I told it the file path.