I am not sure leaving it at the airport in Bangkok is very practical. Once it is shipped, either you or an agent will have to clear customs and retrieve your bike at the Bangkok airport right away. And the Bangkok airport is known for corruption, so its best to get it out of there and into your hands as soon as possible.
One option is to ship it to Bangkok, clear customs and store it somewhere else besides the airport, then go travel. There is probably a time limit on how long your bike can stay in Thailand, but I forget what it is. I would contact the Thailand Community in the "Community" link on the left for some advice on this, Maarten can probably be of help.
The other option is to leave it in Nepal while you do your travelling and come back, get the bike and ship to Bangkok. But there may be an issue with overstaying your carnet on this, however I believe its been done before.
Search the HUBB for information on how long you can leave the bike in either Thailand or Nepal, there should be some posts there.