The only native way to construct a range reference from a string in a formula is by using INDIRECT(). However, INDIRECT() will only work when the other workbook is open; if it is closed then it will return an error.

Without re-inventing the wheel, you could go to Edit | Links | Update values and browse to the correct file. Or perhaps you could give Jan Karel Pieterse's link fixing utility a try? This shouldn't happen very often, right?