[TxMt] command output snippet newline

[thomas Aylott]

hello.
How do I keep a command output from sending in an extra newline?

I've got a command like this:
echo $\{1:`expr $TM_SELECTED_TEXT + 1`\}
Input: Selected Text
Output: insert as snippet
Activation: ctrl-up
Scope constant.numeric

But it's no good unless I can figure out how to keep that pesky  
newline from jumping in my face.

Thanks