Project 2007 Importing a XLS into Project

I inhereted this macros and the team wants to change it...

I am trying to open an excel document and assign the items to the project it was working fine for a while and now as i am testing it i get the error below.  The xls document is not open.

dialogResult = FileOpenEx(Sheet:="STIM Import", FormatID:="MSProject.xls5.9", Map:="STIM ", DoNotLoadFromEnterprise:=True)

First of all can some explain the Map:= parameter -- my problem may be in this parameter as I dont really know what the Map is refering to...

I keep getting the following error -2147417848 : Method FileOpenEx of object =MSProject' failed : Error on line 1150 of cours the line about is 1150

Kathy Tullis