IDE.exe start toobar button fails when % in script path

[Stefano Piccardi]

WinXP SP3 English, when a btm script full path includes a literal string %something%, ide.exe 12.10 can't start debugging the script file.
Replicate: Open a btm file which resides in a filepath that includes the literal string %something%. Then press the green triangle Start button in the ide toolbar to begin debugging. The associated TCC window complains that it can't find the btm script file, even though it is fully loaded in the ide window. TCC shows a full path where the null string has replaced the literal string %something%.