Export to .Jpg file name option

Hello, I'm trying to make a macro that exports my active selection as a .Jpg into a specific folder. Luckily I found (almost) exactly what I wanted in an old discussion with this code (Written by Shelby Moore):

Sub ExportJPG()
Dim opt As New StructExportOptions

ActiveDocument.Unit = cdrInch

opt.AntiAliasingType = cdrNormalAntiAliasing
opt.ImageType = cdrRGBColorImage
opt.Overwrite = True
opt.ResolutionX = 300
opt.ResolutionY = 300
opt.SizeX = opt.ResolutionX * ActiveSelectionRange.SizeWidth
opt.SizeY = opt.ResolutionY * ActiveSelectionRange.SizeHeight

ActiveDocument.Export "C:\Users\Jaspo\Documents\Corel\Pics\Export.jpg", cdrJPEG, cdrSelection, opt
End Sub

The only thing with this is, it overwrites my last exported photo with the same name "Export.jpg". I'd like to have a message box come up where I could name the file whatever I want. 

I'm still pretty new to macros but learning a little more every day through online tutorials and looking through old discussions. But at this point I don't know enough to just write the code from scratch.