A somewhat unusual custom dynamic

[Andrew Bernard]

Here's a custom dynamic I need (the usual New Complexity complications...):

pptopppdashText = \markup {
  \line {  pp \normal-text > ppp―  }
}
pptopppdash =
\tweak DynamicText.self-alignment-X #LEFT
#(make-dynamic-script pptopppdashText)

The greater than sign is my naive attempt to include a hairpin. The
question is, how could one put a 'proper' hairpin, with a view to
being able to make it longer?

Andrew