Getting cell data into macro filespec

[LonnieP]

I've got a drive letter (including the colon) in cell P7 - It's always in P7.
I've got a file name in (including .xls) in cell W5 - It's always in W5.
My current hard coded line is:
Workbooks.Open Filename:=("C:\Calcblox\pool\bm1.xls"), updatelinks:=3

Question, how do I get the text items in cells P7 and W5 into this line of code.
Both items are variable under user control.
I think I'm missing something really simple here.

Lonnie