I use a macro to populate other languages with existing translations from English when those languages are not fully translated. I think this macro should work for you too.
However, you still have to include the desired prefix in the macro.

Thanks for the answer.

Can you share the code of the macro how to fill translation texts from other language please?

I would then adjust it for my purposes.

It's long and partially in German, can I send you this macro to an e-mail?

Thanks Birgit Puchner for the code you provided me. It really helped me.

And this is the solution:

Sub Main
	Dim prj As PslProject
	Set prj = PSL.ActiveProject
	Dim dstTransList As PslTransList
	Set dstTransList = PSL.ActiveTransList
	Dim dstSourceList As PslSourceList
	Set dstSourceList = prj.SourceLists.Item(2)

	' Get English translation List
	Dim engTransList As PslTransList
	For i = 1 To prj.TransLists.Count
		Set engTransList = prj.TransLists.Item(i)
		If engTransList.SourceList.ListID = dstSourceList.ListID And engTransList.Language.LangID = 9 Then
			Exit For
		End If
	Next i

	' Populate dummy translation
	For j = 1 To dstTransList.StringCount
		Dim dstTransString As PslTransString
		Set dstTransString = dstTransList.String(j)
		If dstTransString.State(pslStateReadOnly) = False And dstTransString.State(pslStateHidden) = False And dstTransString.State(pslStateLocked) = False And dstTransString.State(pslStateTranslated) = False Then
			Dim engTransString As PslTransString
			Set engTransString = engTransList.String(j)
			If engTransString.State(pslStateTranslated) Then
				dstTransString.Text = "▲" + engTransString.Text
			Else
				dstTransString.Text = "▼" + dstTransString.Text
			End If
			dstTransString.State(pslStateTranslated) = True
		End If
	Next j

	dstTransList.Save
End Sub