The error you originally showed was because of the comma.
The number of decimal places does not matter.

The two types of stimuli need to be in separate files. The
attached example "with 8 runs and 2 modulators" does not
always have 2 modulators. The very first entry has only 1,
and line #4 (1-based) still has both types:

15.0157*10,7:26.3955 141.012*10:20.2902

The first event has "*10,7" for 2 modulators (which should
be changed to "*10*7" in any case), while the second event
has only "*10" for 1 modulator.

You would get a more clear error by first replacing all
commas with asterisks. The "unusable token" error happens
because of those commas.

Use the format: t1*R1*R2:d .

- rick