Loop through the files:
Dim fso, fld, fil, FoundIt
Set fso = CreateObject("Scripting.FileSystemObject")
Set fld = fso.GetFolder("F:\mgr\log")
FoundIt = False
For Each fil In fld.Files
If LCase(Left(fil.Name, 7)) = "speecca" and LCase(Right(fil.Name, 4)) = ".txt" Then
FoundIt = True
Exit For
End If
Next
If FoundIt Then oktorun Else notoktorun
Set fil = Nothing
Set fld = Nothing
Set fso = Nothing