Dim ExcelApp As Excel.Application

Set ExcelApp = New Excel.Application
ExcelApp.Workbooks.Add

ExcelApp.Cells(X,Y) = "Hello, World!"
ExcelApp.Cells(X,Y).Font.Underline = True
'.Cells(X,Y).Font.Bold = True

Dim ExcelApp As Excel.Application

Set ExcelApp = New Excel.Application
ExcelApp.Workbooks.Add

ExcelApp.Cells(X,Y) = "Hello, World!"
ExcelApp.Cells(X,Y).Font.Underline = True

With ExcelApp.Cells(X,Y).Characters(Start:= 2 , Length:= 3 ).Font
    
    '.Name = "Arial Cyr"
    '.FontStyle = "обычный"
    '.Size = 10
    '.Strikethrough = False
    '.Superscript = False
    '.Subscript = False
    '.OutlineFont = False
    '.Shadow = False
    '.Underline = xlUnderlineStyleNone
    .ColorIndex =  46 
        
End With