Hello all, is there an easy way to export a BOM from an assembly and maintain the formatting of the text?

I'm basing my code on this example:

When I call this line: bExcelResult = swTableAnno.SaveAsText(xlSaveName, vbTab) it throws an error in excel upon opening that says the extensions doesn't match the format, if I click yes to proceed,  I loose all of the formatting from the SW BOM.

I want to avoid re-formatting programatically if at all possible, and my ultimate goal is to save as a .xlsx file.