adding double digit indication to note

[Jan Jaap Badon]

When entering the score of a symphony, I encountered a problem with entering 
number indications above notes. In a search, I could not find anything in 
the archives.

In a piece, I have to play 15 consecutive tied notes. To make it easier to 
keep track of how many I played already, I want to add numbers above for 
counting. I first entered it like this:

g1~-1 g1~-2 g1~-3 ...  g1~-14 g1~-15

Unfortunately, when I invoked Lilypond after that, it did not work. After 
some testing, it appeared that numbers with more than one digit are not 
accepted. The only way to get it to work is to enter it like:

g1~-1 g1~-2 g1~-3 ... g1~^\markup {\finger "14"} g1~^\markup {\finger "15"}

Is there any other way to do this? It appears a bit cumbersome to me. Is 
there a reason for only accepting one digit in the numbers above the notes?

Thank you for your attention and effort,

Yours,
   Jan Jaap