How do I return a range of Members?

We have a large flat hierarchy, members starting with Px_1000 to Px_9999. For example, P1_1000_27 Project 1, P5_1001 Project Yellow.... P7_9999 Project Bob. The numbers are unique (no two same number). We want a report that allows users to enter a "From" - "To" to pull back members in that range. For instance, only pull back members in the range "From" 500 To "532". Have an XFBR where I'm parsing the string, that's working, looping through and but only returning the number. The issue is that I need the entire string and description of the member. That's where I'm stuck. If anyone has done this before, would very much like know how you coded the XFBR. Thank you!