Macro to run another macro in different workbook

[squeakums]

Okay, so I've been researching this, and I have a lot of macros written in other workbooks and a primary workbook with macros as well.
I feel like this is so simple that I am missing it... but I have the code below to open another file and run the macro in that file. I've tried just simply Call combinepv
but that errors out so I wrote the code below and that errors out as well. Please let me know your thoughts on an easy way to run this macro in another workbook.

    ChDir "O:\test\Formula Files"
Workbooks.Open Filename:= _
        "O:\test\Test EPO.xlsm", UpdateLinks:=0

    Sheets("Instructions").Select
Dim WorkbookName As String
Dim MacroName As String
WorkbookName = "Test EPO.xlsm"
MacroName = "CombinePV"

 

[steve the fish]

Try:

Application.Run "'Test EPO.xlsm'!CombinePV"

 

[squeakums]

Thank you that works, I tried that earlier but was missing the ''