thanks everyone for the help. you all helped me go the direction I needed.
Frank, setting the active level would work if I wasn't setting a default level for rasters in my preferences. but the get element from raster is what I needed.
this is what I ended up with.
Dim oRastMan As RasterManager, oRast As Raster
Dim strTiffPath As String, oLevel As Level, oElement as Element
set oRastMan = RasterManager
Set oLevel = ActiveDesignFile.Levels("RS_Raster2")
strTiffpath = "Put path to file here"
Set oRast =oRastMan.Rasters.Attach(strTiffPath)
Set oElement = oRastMan.Rasters.GetElementFromRaster(oRast)
oElement.Level = oLevel
oElement.Rewrite
